<?xml version="1.0" encoding="utf-8"?>
<!--XBRL document created with Toppan Merrill Bridge  11.4.0.1 -->
<!--Based on XBRL 2.1-->
<!--Created on: 8/6/2026 3:22:42 PM-->
<!--Modified on: 8/6/2026 3:22:42 PM-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DocumentDocumentAndEntityInformation" roleURI="http://www.oldsecond.com/role/DocumentDocumentAndEntityInformation" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedBalanceSheets" roleURI="http://www.oldsecond.com/role/StatementConsolidatedBalanceSheets" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedBalanceSheetsParenthetical" roleURI="http://www.oldsecond.com/role/StatementConsolidatedBalanceSheetsParenthetical" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedStatementsOfIncome" roleURI="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfIncome" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedStatementsOfComprehensiveIncome" roleURI="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfComprehensiveIncome" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedStatementsOfCashFlows" roleURI="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfCashFlows" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedStatementsOfChangesInStockholdersEquity" roleURI="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#StatementConsolidatedStatementsOfChangesInStockholdersEquityParenthetical" roleURI="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquityParenthetical" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBasisOfPresentationAndChangesInSignificantAccountingPolicies" roleURI="http://www.oldsecond.com/role/DisclosureBasisOfPresentationAndChangesInSignificantAccountingPolicies" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureAcquisition" roleURI="http://www.oldsecond.com/role/DisclosureAcquisition" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSecurities" roleURI="http://www.oldsecond.com/role/DisclosureSecurities" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoans" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoans" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureOtherRealEstateOwned" roleURI="http://www.oldsecond.com/role/DisclosureOtherRealEstateOwned" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDeposits" roleURI="http://www.oldsecond.com/role/DisclosureDeposits" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBorrowings" roleURI="http://www.oldsecond.com/role/DisclosureBorrowings" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureJuniorSubordinatedDebentures" roleURI="http://www.oldsecond.com/role/DisclosureJuniorSubordinatedDebentures" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEquityCompensationPlans" roleURI="http://www.oldsecond.com/role/DisclosureEquityCompensationPlans" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEarningsPerShare" roleURI="http://www.oldsecond.com/role/DisclosureEarningsPerShare" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureRegulatoryCapitalMatters" roleURI="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMatters" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurements" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurements" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValuesOfFinancialInstruments" roleURI="http://www.oldsecond.com/role/DisclosureFairValuesOfFinancialInstruments" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRisk" roleURI="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRisk" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSegmentInformation" roleURI="http://www.oldsecond.com/role/DisclosureSegmentInformation" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBasisOfPresentationAndChangesInSignificantAccountingPoliciesPolicies" roleURI="http://www.oldsecond.com/role/DisclosureBasisOfPresentationAndChangesInSignificantAccountingPoliciesPolicies" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureAcquisitionTables" roleURI="http://www.oldsecond.com/role/DisclosureAcquisitionTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSecuritiesTables" roleURI="http://www.oldsecond.com/role/DisclosureSecuritiesTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansTables" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureOtherRealEstateOwnedTables" roleURI="http://www.oldsecond.com/role/DisclosureOtherRealEstateOwnedTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDepositsTables" roleURI="http://www.oldsecond.com/role/DisclosureDepositsTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBorrowingsTables" roleURI="http://www.oldsecond.com/role/DisclosureBorrowingsTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEquityCompensationPlansTables" roleURI="http://www.oldsecond.com/role/DisclosureEquityCompensationPlansTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEarningsPerShareTables" roleURI="http://www.oldsecond.com/role/DisclosureEarningsPerShareTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureRegulatoryCapitalMattersTables" roleURI="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurementsTables" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValuesOfFinancialInstrumentsTables" roleURI="http://www.oldsecond.com/role/DisclosureFairValuesOfFinancialInstrumentsTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskTables" roleURI="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskTables" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBasisOfPresentationAndChangesInSignificantAccountingPoliciesDetails" roleURI="http://www.oldsecond.com/role/DisclosureBasisOfPresentationAndChangesInSignificantAccountingPoliciesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureAcquisitionDetails" roleURI="http://www.oldsecond.com/role/DisclosureAcquisitionDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureAcquisitionBancorpFinancialAssetsAcquiredAndLiabilitiesAssumedDetails" roleURI="http://www.oldsecond.com/role/DisclosureAcquisitionBancorpFinancialAssetsAcquiredAndLiabilitiesAssumedDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureAcquisitionBancorpFinancialScheduleOfPurchasePriceOfLoansAtAcquisitionDetails" roleURI="http://www.oldsecond.com/role/DisclosureAcquisitionBancorpFinancialScheduleOfPurchasePriceOfLoansAtAcquisitionDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSecuritiesAmortizedCostAndFairValueDetails" roleURI="http://www.oldsecond.com/role/DisclosureSecuritiesAmortizedCostAndFairValueDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSecuritiesContractualMaturitiesDetails" roleURI="http://www.oldsecond.com/role/DisclosureSecuritiesContractualMaturitiesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSecuritiesUnrealizedLossPositionsDetails" roleURI="http://www.oldsecond.com/role/DisclosureSecuritiesUnrealizedLossPositionsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansMajorClassificationsDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansMajorClassificationsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansMajorClassificationsLoanConcentrationsDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansMajorClassificationsLoanConcentrationsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansCollateralDependentLoansDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansCollateralDependentLoansDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansAgingAnalysisDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansAgingAnalysisDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansNonaccrualsDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansNonaccrualsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansCreditQualityDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansCreditQualityDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansChargeOffsActivityByLoanTypeDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansChargeOffsActivityByLoanTypeDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureLoansAndAllowanceForCreditLossesOnLoansLoanModificationsDetails" roleURI="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansLoanModificationsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureOtherRealEstateOwnedDetails" roleURI="http://www.oldsecond.com/role/DisclosureOtherRealEstateOwnedDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDepositsClassificationsOfDepositsDetails" roleURI="http://www.oldsecond.com/role/DisclosureDepositsClassificationsOfDepositsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBorrowingsSummaryDetails" roleURI="http://www.oldsecond.com/role/DisclosureBorrowingsSummaryDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureBorrowingsAdditionalInformationDetails" roleURI="http://www.oldsecond.com/role/DisclosureBorrowingsAdditionalInformationDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureJuniorSubordinatedDebenturesIssuanceDetails" roleURI="http://www.oldsecond.com/role/DisclosureJuniorSubordinatedDebenturesIssuanceDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEquityCompensationPlansDetails" roleURI="http://www.oldsecond.com/role/DisclosureEquityCompensationPlansDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEquityCompensationPlansRestrictedStockAndRsusDetails" roleURI="http://www.oldsecond.com/role/DisclosureEquityCompensationPlansRestrictedStockAndRsusDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureEarningsPerShareReconciliationDetails" roleURI="http://www.oldsecond.com/role/DisclosureEarningsPerShareReconciliationDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureRegulatoryCapitalMattersDetails" roleURI="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureRegulatoryCapitalMattersCapitalLevelsAndIndustryDefinedRegulatoryMinimumsDetails" roleURI="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersCapitalLevelsAndIndustryDefinedRegulatoryMinimumsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureRegulatoryCapitalMattersDividendRestrictionsDetails" roleURI="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersDividendRestrictionsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurementsDetails" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurementsRecurringDetails" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsRecurringDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurementsChangesInLevel3Details" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsChangesInLevel3Details" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurementsQuantitativeAndQualitativeInformationDetails" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsQuantitativeAndQualitativeInformationDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValueMeasurementsNonrecurringDetails" roleURI="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsNonrecurringDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureFairValuesOfFinancialInstrumentsDetails" roleURI="http://www.oldsecond.com/role/DisclosureFairValuesOfFinancialInstrumentsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskDetails" roleURI="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskEffectOfFairValueAndCashFlowHedgeAccountingDetails" roleURI="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskEffectOfFairValueAndCashFlowHedgeAccountingDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskCommitmentsDetails" roleURI="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskCommitmentsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="osbc-20260630.xsd#DisclosureSegmentInformationDetails" roleURI="http://www.oldsecond.com/role/DisclosureSegmentInformationDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#InsiderTradingArrangements" roleURI="http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements" xmlns="http://www.xbrl.org/2003/linkbase" />
  <presentationLink xlink:role="http://www.oldsecond.com/role/DocumentDocumentAndEntityInformation" xlink:type="extended" xlink:title="995200090 - Document - Document and Entity Information" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DocumentAndEntityInformationAbstract" xlink:label="osbc_DocumentAndEntityInformationAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentType" xlink:label="dei_DocumentType_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentType_639216265577848000" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentQuarterlyReport" xlink:label="dei_DocumentQuarterlyReport_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentQuarterlyReport_639216265577848000" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentTransitionReport_639216265577848000" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentPeriodEndDate_639216265577848000" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityFileNumber_639216265577848000" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityRegistrantName_639216265577848000" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityIncorporationStateCountryCode_639216265577848000" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityTaxIdentificationNumber_639216265577848000" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityAddressAddressLine1_639216265577848000" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityAddressCityOrTown_639216265577848000" order="10" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityAddressStateOrProvince_639216265577848000" order="11" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityAddressPostalZipCode_639216265577848000" order="12" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_CityAreaCode_639216265577848000" order="13" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_LocalPhoneNumber_639216265577848000" order="14" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_Security12bTitle_639216265577848000" order="15" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_TradingSymbol_639216265577848000" order="16" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_SecurityExchangeName_639216265577848000" order="17" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityCurrentReportingStatus_639216265577848000" order="18" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityInteractiveDataCurrent_639216265577848000" order="19" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityFilerCategory_639216265577848000" order="20" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntitySmallBusiness_639216265577848000" order="21" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityEmergingGrowthCompany_639216265577848000" order="22" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityShellCompany_639216265577848000" order="23" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityCommonStockSharesOutstanding_639216265577848000" order="24" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_CurrentFiscalYearEndDate_639216265577848000" order="25" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentFiscalYearFocus_639216265577848000" order="26" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_DocumentFiscalPeriodFocus_639216265577848000" order="27" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_EntityCentralIndexKey_639216265577848000" order="28" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DocumentAndEntityInformationAbstract" xlink:to="dei_AmendmentFlag_639216265577848000" order="29" use="optional" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedBalanceSheets" xlink:type="extended" xlink:title="995200100 - Statement - Consolidated Balance Sheets" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AssetsAbstract_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndDueFromBanks" xlink:label="us-gaap_CashAndDueFromBanks_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_CashAndDueFromBanks_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestBearingDepositsInBanks" xlink:label="us-gaap_InterestBearingDepositsInBanks_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_InterestBearingDepositsInBanks_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:label="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_639216265577848000" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoansReceivableHeldForSaleAmount" xlink:label="us-gaap_LoansReceivableHeldForSaleAmount_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_LoansReceivableHeldForSaleAmount_639216265577848000" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265577848000" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265577848000" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss_639216265577848000" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_639216265577848000" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAcquiredThroughForeclosure" xlink:label="us-gaap_RealEstateAcquiredThroughForeclosure_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_RealEstateAcquiredThroughForeclosure_639216265577848000" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ServicingAssetAtFairValueAmount" xlink:label="us-gaap_ServicingAssetAtFairValueAmount_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_ServicingAssetAtFairValueAmount_639216265577848000" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_Goodwill_639216265577848000" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_639216265577848000" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BankOwnedLifeInsurance" xlink:label="us-gaap_BankOwnedLifeInsurance_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_BankOwnedLifeInsurance_639216265577848000" order="15" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredIncomeTaxAssetsNet" xlink:label="us-gaap_DeferredIncomeTaxAssetsNet_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_DeferredIncomeTaxAssetsNet_639216265577848000" order="16" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssets" xlink:label="us-gaap_OtherAssets_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_OtherAssets_639216265577848000" order="17" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract_639216265577848000" xlink:to="us-gaap_Assets_639216265577848000" order="18" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAbstract" xlink:label="us-gaap_LiabilitiesAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesAbstract_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsAbstract" xlink:label="us-gaap_DepositsAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_DepositsAbstract_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestBearingDepositLiabilities" xlink:label="us-gaap_NoninterestBearingDepositLiabilities_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsAbstract_639216265577848000" xlink:to="us-gaap_NoninterestBearingDepositLiabilities_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestBearingDepositLiabilitiesAbstract" xlink:label="us-gaap_InterestBearingDepositLiabilitiesAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsAbstract_639216265577848000" xlink:to="us-gaap_InterestBearingDepositLiabilitiesAbstract_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestBearingDepositLiabilitiesDomestic" xlink:label="us-gaap_InterestBearingDepositLiabilitiesDomestic_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestBearingDepositLiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_InterestBearingDepositLiabilitiesDomestic_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TimeDeposits" xlink:label="us-gaap_TimeDeposits_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestBearingDepositLiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_TimeDeposits_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Deposits" xlink:label="us-gaap_Deposits_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsAbstract_639216265577848000" xlink:to="us-gaap_Deposits_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherShortTermBorrowings" xlink:label="us-gaap_OtherShortTermBorrowings_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_OtherShortTermBorrowings_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust" xlink:label="us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubordinatedDebt" xlink:label="us-gaap_SubordinatedDebt_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_SubordinatedDebt_639216265577848000" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="7" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NotesAndLoansPayable" xlink:label="us-gaap_NotesAndLoansPayable_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_NotesAndLoansPayable_639216265577848000" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilities" xlink:label="us-gaap_OtherLiabilities_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_OtherLiabilities_639216265577848000" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract_639216265577848000" xlink:to="us-gaap_Liabilities_639216265577848000" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_639216265577848000" xlink:to="us-gaap_CommonStockValue_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_639216265577848000" xlink:to="us-gaap_AdditionalPaidInCapital_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_639216265577848000" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_639216265577848000" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockCommonValue" xlink:label="us-gaap_TreasuryStockCommonValue_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_639216265577848000" xlink:to="us-gaap_TreasuryStockCommonValue_639216265577848000" order="5" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract_639216265577848000" xlink:to="us-gaap_StockholdersEquity_639216265577848000" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedBalanceSheetsParenthetical" xlink:type="extended" xlink:title="995200105 - Statement - Consolidated Balance Sheets (Parenthetical)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesAuthorized_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesIssued_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesOutstanding_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockCommonShares" xlink:label="us-gaap_TreasuryStockCommonShares_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_TreasuryStockCommonShares_639216265577848000" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfIncome" xlink:type="extended" xlink:title="995200200 - Statement - Consolidated Statements of Income" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_StatementTable_639216265577848000" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_639216265577848000" xlink:to="srt_ProductOrServiceAxis_639216265577848000" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductOrServiceAxis_639216265577848000" xlink:to="srt_ProductsAndServicesDomain_639216265577848000" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiduciaryAndTrustMember" xlink:label="us-gaap_FiduciaryAndTrustMember_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_639216265577848000" xlink:to="us-gaap_FiduciaryAndTrustMember_639216265577848000" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositAccountMember" xlink:label="us-gaap_DepositAccountMember_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_639216265577848000" xlink:to="us-gaap_DepositAccountMember_639216265577848000" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MortgageBankingMember" xlink:label="us-gaap_MortgageBankingMember_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_639216265577848000" xlink:to="us-gaap_MortgageBankingMember_639216265577848000" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageServicingMember" xlink:label="osbc_MortgageServicingMember_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain_639216265577848000" xlink:to="osbc_MortgageServicingMember_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_639216265577848000" xlink:to="us-gaap_StatementLineItems_639216265577848000" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndDividendIncomeOperatingAbstract" xlink:label="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio" xlink:label="us-gaap_InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" xlink:to="us-gaap_InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages" xlink:label="us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" xlink:to="us-gaap_InterestAndFeeIncomeLoansHeldForSaleMortgages_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndDividendIncomeSecuritiesByTaxableStatusAbstract" xlink:label="us-gaap_InterestAndDividendIncomeSecuritiesByTaxableStatusAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" xlink:to="us-gaap_InterestAndDividendIncomeSecuritiesByTaxableStatusAbstract_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestIncomeSecuritiesTaxable" xlink:label="us-gaap_InterestIncomeSecuritiesTaxable_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeSecuritiesByTaxableStatusAbstract_639216265577848000" xlink:to="us-gaap_InterestIncomeSecuritiesTaxable_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt" xlink:label="us-gaap_InterestIncomeSecuritiesTaxExempt_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeSecuritiesByTaxableStatusAbstract_639216265577848000" xlink:to="us-gaap_InterestIncomeSecuritiesTaxExempt_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendIncomeOperating" xlink:label="us-gaap_DividendIncomeOperating_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" xlink:to="us-gaap_DividendIncomeOperating_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:label="us-gaap_InterestIncomeDepositsWithFinancialInstitutions_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" xlink:to="us-gaap_InterestIncomeDepositsWithFinancialInstitutions_639216265577848000" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndDividendIncomeOperating" xlink:label="us-gaap_InterestAndDividendIncomeOperating_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestAndDividendIncomeOperatingAbstract_639216265577848000" xlink:to="us-gaap_InterestAndDividendIncomeOperating_639216265577848000" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseAbstract" xlink:label="us-gaap_InterestExpenseAbstract_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_InterestExpenseAbstract_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits" xlink:label="us-gaap_InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseNOWAccountsMoneyMarketAccountsAndSavingsDeposits_639216265577848000" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseTimeDeposits" xlink:label="us-gaap_InterestExpenseTimeDeposits_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseTimeDeposits_639216265577848000" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseSecuritiesSoldUnderAgreementsToRepurchase" xlink:label="us-gaap_InterestExpenseSecuritiesSoldUnderAgreementsToRepurchase_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseSecuritiesSoldUnderAgreementsToRepurchase_639216265577848000" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseOtherShortTermBorrowings" xlink:label="us-gaap_InterestExpenseOtherShortTermBorrowings_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseOtherShortTermBorrowings_639216265577848000" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseJuniorSubordinatedDebentures" xlink:label="us-gaap_InterestExpenseJuniorSubordinatedDebentures_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseJuniorSubordinatedDebentures_639216265577848000" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseSubordinatedNotesAndDebentures" xlink:label="us-gaap_InterestExpenseSubordinatedNotesAndDebentures_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseSubordinatedNotesAndDebentures_639216265577848000" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InterestExpenseNotesPayableAndLoansPayable" xlink:label="osbc_InterestExpenseNotesPayableAndLoansPayable_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="osbc_InterestExpenseNotesPayableAndLoansPayable_639216265577848000" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseOperating" xlink:label="us-gaap_InterestExpenseOperating_639216265577848000" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InterestExpenseAbstract_639216265577848000" xlink:to="us-gaap_InterestExpenseOperating_639216265577848000" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet_639216265577943278" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_InterestIncomeExpenseNet_639216265577943278" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses" xlink:label="us-gaap_ProvisionForLoanLeaseAndOtherLosses_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_ProvisionForLoanLeaseAndOtherLosses_639216265577943857" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" xlink:label="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_639216265577943857" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestIncomeAbstract" xlink:label="us-gaap_NoninterestIncomeAbstract_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_NoninterestIncomeAbstract_639216265577943857" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_639216265577943857" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MortgageServicingRightsMSRImpairmentRecovery" xlink:label="us-gaap_MortgageServicingRightsMSRImpairmentRecovery_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="us-gaap_MortgageServicingRightsMSRImpairmentRecovery_639216265577943857" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainLossOnSaleOfMortgageLoans" xlink:label="us-gaap_GainLossOnSaleOfMortgageLoans_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="us-gaap_GainLossOnSaleOfMortgageLoans_639216265577943857" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue" xlink:label="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_639216265577943857" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CardInterchangeIncomeDebit" xlink:label="osbc_CardInterchangeIncomeDebit_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="osbc_CardInterchangeIncomeDebit_639216265577943857" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestIncomeOtherOperatingIncome" xlink:label="us-gaap_NoninterestIncomeOtherOperatingIncome_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="us-gaap_NoninterestIncomeOtherOperatingIncome_639216265577943857" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestIncome" xlink:label="us-gaap_NoninterestIncome_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestIncomeAbstract_639216265577943857" xlink:to="us-gaap_NoninterestIncome_639216265577943857" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestExpenseAbstract" xlink:label="us-gaap_NoninterestExpenseAbstract_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_NoninterestExpenseAbstract_639216265577943857" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LaborAndRelatedExpense" xlink:label="us-gaap_LaborAndRelatedExpense_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_LaborAndRelatedExpense_639216265577943857" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquipmentExpense" xlink:label="us-gaap_EquipmentExpense_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_EquipmentExpense_639216265577943857" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommunicationsAndInformationTechnology" xlink:label="us-gaap_CommunicationsAndInformationTechnology_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_CommunicationsAndInformationTechnology_639216265577943857" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FederalDepositInsuranceCorporationPremiumExpenseIncludingAdjustments" xlink:label="osbc_FederalDepositInsuranceCorporationPremiumExpenseIncludingAdjustments_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="osbc_FederalDepositInsuranceCorporationPremiumExpenseIncludingAdjustments_639216265577943857" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NetTellerAndBillPayingExpense" xlink:label="osbc_NetTellerAndBillPayingExpense_639216265577943857" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="osbc_NetTellerAndBillPayingExpense_639216265577943857" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralInsuranceExpense" xlink:label="us-gaap_GeneralInsuranceExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_GeneralInsuranceExpense_639216265577959664" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_AmortizationOfIntangibleAssets_639216265577959664" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketingAndAdvertisingExpense" xlink:label="us-gaap_MarketingAndAdvertisingExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_MarketingAndAdvertisingExpense_639216265577959664" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DebitCardInterchangeExpense" xlink:label="osbc_DebitCardInterchangeExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="osbc_DebitCardInterchangeExpense_639216265577959664" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProfessionalFees" xlink:label="us-gaap_ProfessionalFees_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_ProfessionalFees_639216265577959664" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ConsumerCreditExpense" xlink:label="osbc_ConsumerCreditExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="osbc_ConsumerCreditExpense_639216265577959664" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherRealEstateOwnedExpense" xlink:label="osbc_OtherRealEstateOwnedExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="osbc_OtherRealEstateOwnedExpense_639216265577959664" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherNoninterestExpense" xlink:label="us-gaap_OtherNoninterestExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_OtherNoninterestExpense_639216265577959664" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestExpense" xlink:label="us-gaap_NoninterestExpense_639216265577959664" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoninterestExpenseAbstract_639216265577943857" xlink:to="us-gaap_NoninterestExpense_639216265577959664" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639216265577970558" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_639216265577970558" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit_639216265577972025" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_IncomeTaxExpenseBenefit_639216265577972025" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_639216265577972025" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_639216265577972025" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_639216265577972025" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_EarningsPerShareBasic_639216265577972025" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_639216265577972025" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_EarningsPerShareDiluted_639216265577972025" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockDividendsPerShareDeclared" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared_639216265577977308" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265577848000" xlink:to="us-gaap_CommonStockDividendsPerShareDeclared_639216265577977308" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended" xlink:title="995200300 - Statement - Consolidated Statements of Comprehensive Income" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_639216265577981657" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_NetIncomeLoss_639216265577981657" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_639216265577982449" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_639216265577982449" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_639216265577982869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_639216265577982869" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_639216265577983687" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_639216265577983687" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherComprehensiveIncomeAvailableForSaleSecuritiesUnrealizedHoldingGainLossNetReclassificationAdjustmentForAmountsRealizedAfterTax" xlink:label="osbc_OtherComprehensiveIncomeAvailableForSaleSecuritiesUnrealizedHoldingGainLossNetReclassificationAdjustmentForAmountsRealizedAfterTax_639216265577984474" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="osbc_OtherComprehensiveIncomeAvailableForSaleSecuritiesUnrealizedHoldingGainLossNetReclassificationAdjustmentForAmountsRealizedAfterTax_639216265577984474" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTaxParent" xlink:label="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTaxParent_639216265577985332" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTaxParent_639216265577985332" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent" xlink:label="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent_639216265577986110" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTaxParent_639216265577986110" order="7" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent" xlink:label="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_639216265577986935" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent_639216265577986935" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_639216265577987714" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax_639216265577987714" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_639216265577988538" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax_639216265577988538" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfCashFlows" xlink:type="extended" xlink:title="995200400 - Statement - Consolidated Statements of Cash Flows" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_639216265577991692" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_639216265577991692" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_639216265577992440" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_639216265577991692" xlink:to="us-gaap_NetIncomeLoss_639216265577992440" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_639216265577991692" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_639216265577993961" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_639216265577993961" order="1" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="8" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses" xlink:label="us-gaap_ProvisionForLoanLeaseAndOtherLosses_639216265577994716" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_ProvisionForLoanLeaseAndOtherLosses_639216265577994716" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="9" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale" xlink:label="us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale_639216265577995529" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale_639216265577995529" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSaleOfLoansHeldForSale" xlink:label="us-gaap_ProceedsFromSaleOfLoansHeldForSale_639216265577996269" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_ProceedsFromSaleOfLoansHeldForSale_639216265577996269" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainLossOnSaleOfMortgageLoans" xlink:label="us-gaap_GainLossOnSaleOfMortgageLoans_639216265577997051" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_GainLossOnSaleOfMortgageLoans_639216265577997051" order="5" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MortgageServicingRightsMSRImpairmentRecovery" xlink:label="us-gaap_MortgageServicingRightsMSRImpairmentRecovery_639216265577997858" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_MortgageServicingRightsMSRImpairmentRecovery_639216265577997858" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="8" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NetDiscountAccretionOfPurchaseAccountingAdjustmentOnLoans" xlink:label="osbc_NetDiscountAccretionOfPurchaseAccountingAdjustmentOnLoans_639216265577998996" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_NetDiscountAccretionOfPurchaseAccountingAdjustmentOnLoans_639216265577998996" order="7" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue" xlink:label="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_639216265577999736" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_639216265577999736" order="8" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_GainsLossesOnSalesOfOtherRealEstateNetOfChangesToValuationAdjustment" xlink:label="osbc_GainsLossesOnSalesOfOtherRealEstateNetOfChangesToValuationAdjustment_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_GainsLossesOnSalesOfOtherRealEstateNetOfChangesToValuationAdjustment_639216265578000565" order="9" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateOwnedValuationAllowanceProvision1" xlink:label="us-gaap_RealEstateOwnedValuationAllowanceProvision1_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_RealEstateOwnedValuationAllowanceProvision1_639216265578000565" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_DepreciationDepletionAndAmortization_639216265578000565" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_IncreaseDecreaseInOperatingLeaseRightOfUseAsset" xlink:label="osbc_IncreaseDecreaseInOperatingLeaseRightOfUseAsset_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_IncreaseDecreaseInOperatingLeaseRightOfUseAsset_639216265578000565" order="12" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_AmortizationOfIntangibleAssets_639216265578000565" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:label="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_639216265578000565" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DeferredIncomeTaxExpenseBenefitAfterDeferredTaxAssetValuationAdjustment" xlink:label="osbc_DeferredIncomeTaxExpenseBenefitAfterDeferredTaxAssetValuationAdjustment_639216265578000565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_DeferredIncomeTaxExpenseBenefitAfterDeferredTaxAssetValuationAdjustment_639216265578000565" order="15" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_IncreaseDecreaseInAccruedInterestReceivableAndOtherAssets" xlink:label="osbc_IncreaseDecreaseInAccruedInterestReceivableAndOtherAssets_639216265578005918" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_IncreaseDecreaseInAccruedInterestReceivableAndOtherAssets_639216265578005918" order="16" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NetPremiumAmortizationDiscountAccretionOfPurchaseAccountingAdjustmentsOnLoans" xlink:label="osbc_NetPremiumAmortizationDiscountAccretionOfPurchaseAccountingAdjustmentsOnLoans_639216265578007113" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_NetPremiumAmortizationDiscountAccretionOfPurchaseAccountingAdjustmentsOnLoans_639216265578007113" order="17" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_IncreaseDecreaseInAccruedInterestPayableAndOtherLiabilities" xlink:label="osbc_IncreaseDecreaseInAccruedInterestPayableAndOtherLiabilities_639216265578007919" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="osbc_IncreaseDecreaseInAccruedInterestPayableAndOtherLiabilities_639216265578007919" order="18" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_639216265578009059" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_639216265578009059" order="19" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_639216265578009737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_639216265577993206" xlink:to="us-gaap_ShareBasedCompensation_639216265578009737" order="20" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_639216265578010930" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_639216265577991692" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_639216265578010930" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_639216265578013240" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_639216265578013240" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt" xlink:label="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_639216265578014169" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_639216265578014169" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_639216265578015306" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_639216265578015306" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock" xlink:label="us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock_639216265578016513" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock_639216265578016513" order="4" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="8" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForProceedsFromLoansAndLeases" xlink:label="us-gaap_PaymentsForProceedsFromLoansAndLeases_639216265578017811" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_PaymentsForProceedsFromLoansAndLeases_639216265578017811" order="5" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireLifeInsurancePolicies" xlink:label="us-gaap_PaymentsToAcquireLifeInsurancePolicies_639216265578019175" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_PaymentsToAcquireLifeInsurancePolicies_639216265578019175" order="6" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSaleOfOtherRealEstate" xlink:label="us-gaap_ProceedsFromSaleOfOtherRealEstate_639216265578020306" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_ProceedsFromSaleOfOtherRealEstate_639216265578020306" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets" xlink:label="us-gaap_ProceedsFromSaleOfProductiveAssets_639216265578021424" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_ProceedsFromSaleOfProductiveAssets_639216265578021424" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_639216265578022770" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_639216265578022770" order="9" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_639216265578023981" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_639216265578023981" order="10" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_639216265578025079" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_639216265578012073" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_639216265578025079" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInDeposits" xlink:label="us-gaap_IncreaseDecreaseInDeposits_639216265578027452" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_IncreaseDecreaseInDeposits_639216265578027452" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase" xlink:label="us-gaap_ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase_639216265578028893" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_ProceedsFromPaymentsForInSecuritiesSoldUnderAgreementsToRepurchase_639216265578028893" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ProceedsFromRepaymentsOfOtherShortTermBorrowings" xlink:label="osbc_ProceedsFromRepaymentsOfOtherShortTermBorrowings_639216265578030183" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="osbc_ProceedsFromRepaymentsOfOtherShortTermBorrowings_639216265578030183" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RepaymentsOfSubordinatedDebt" xlink:label="us-gaap_RepaymentsOfSubordinatedDebt_639216265578031296" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_RepaymentsOfSubordinatedDebt_639216265578031296" order="4" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans_639216265578032791" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans_639216265578032791" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfDividendsCommonStock" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_639216265578034206" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_PaymentsOfDividendsCommonStock_639216265578034206" order="6" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_639216265578035383" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_PaymentsForRepurchaseOfCommonStock_639216265578035383" order="7" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_639216265578036861" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_639216265578026348" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_639216265578036861" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_639216265578038373" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_639216265578038373" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_639216265578039435" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_639216265578039435" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_639216265578041279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_639216265578041279" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity" xlink:type="extended" xlink:title="995200500 - Statement - Consolidated Statements of Changes in Stockholders' Equity" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_635337855312267224" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_639216265578045612" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract_635337855312267224" xlink:to="us-gaap_StatementTable_639216265578045612" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_639216265578046646" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_639216265578045612" xlink:to="us-gaap_StatementEquityComponentsAxis_639216265578046646" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember_639216265578047412" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578046646" xlink:to="us-gaap_CommonStockMember_639216265578047412" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember_639216265578048164" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578046646" xlink:to="us-gaap_AdditionalPaidInCapitalMember_639216265578048164" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember_639216265578048960" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578046646" xlink:to="us-gaap_RetainedEarningsMember_639216265578048960" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_639216265578049700" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578046646" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember_639216265578049700" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockCommonMember" xlink:label="us-gaap_TreasuryStockCommonMember_639216265578050489" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578046646" xlink:to="us-gaap_TreasuryStockCommonMember_639216265578050489" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_639216265578050993" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578046646" xlink:to="us-gaap_EquityComponentDomain_639216265578050993" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_639216265578052068" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_639216265578045612" xlink:to="us-gaap_StatementLineItems_639216265578052068" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265578052068" xlink:to="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_639216265578054035" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_StockholdersEquity_639216265578054035" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_639216265578054990" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_CommonStockSharesOutstanding_639216265578054990" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_639216265578055694" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_NetIncomeLoss_639216265578055694" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_639216265578056784" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax_639216265578056784" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsCommonStock" xlink:label="us-gaap_DividendsCommonStock_639216265578057765" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_DividendsCommonStock_639216265578057765" order="5" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_639216265578058645" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_639216265578058645" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_639216265578059668" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_639216265578059668" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_639216265578060662" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_639216265578060662" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_639216265578061679" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_639216265578061679" order="9" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_639216265578062682" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_639216265578062682" order="10" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockValueAcquiredParValueMethod" xlink:label="us-gaap_TreasuryStockValueAcquiredParValueMethod_639216265578063713" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_TreasuryStockValueAcquiredParValueMethod_639216265578063713" order="11" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="us-gaap_TreasuryStockSharesAcquired_639216265578064688" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_TreasuryStockSharesAcquired_639216265578064688" order="12" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_639216265578066328" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_StockholdersEquity_639216265578066328" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_639216265578067597" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_639216265578053029" xlink:to="us-gaap_CommonStockSharesOutstanding_639216265578067597" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquityParenthetical" xlink:type="extended" xlink:title="995200505 - Statement - Consolidated Statements of Changes in Stockholders' Equity (Parenthetical)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable_639216265578070601" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable_639216265578070601" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis_639216265578071636" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_639216265578070601" xlink:to="us-gaap_StatementEquityComponentsAxis_639216265578071636" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_639216265578072411" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis_639216265578071636" xlink:to="us-gaap_EquityComponentDomain_639216265578072411" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_639216265578073136" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain_639216265578072411" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember_639216265578073136" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_639216265578074086" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeMember_639216265578073136" xlink:to="us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_639216265578074086" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember" xlink:label="us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember_639216265578074753" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeMember_639216265578073136" xlink:to="us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember_639216265578074753" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems_639216265578075741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable_639216265578070601" xlink:to="us-gaap_StatementLineItems_639216265578075741" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DividendsDeclaredAndPaidPerShare" xlink:label="osbc_DividendsDeclaredAndPaidPerShare_639216265578076655" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265578075741" xlink:to="osbc_DividendsDeclaredAndPaidPerShare_639216265578076655" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_639216265578076961" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265578075741" xlink:to="us-gaap_StockholdersEquity_639216265578076961" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_639216265578078146" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265578075741" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax_639216265578078146" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_639216265578078794" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems_639216265578075741" xlink:to="us-gaap_StockholdersEquity_639216265578078794" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBasisOfPresentationAndChangesInSignificantAccountingPolicies" xlink:type="extended" xlink:title="995210101 - Disclosure - Basis of Presentation and Changes in Significant Accounting Policies" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock_639216265578081546" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock_639216265578081546" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureAcquisition" xlink:type="extended" xlink:title="995210201 - Disclosure - Acquisition" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_639216265578083798" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock_639216265578083798" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSecurities" xlink:type="extended" xlink:title="995210301 - Disclosure - Securities" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock" xlink:label="us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock_639216265578085913" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:to="us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock_639216265578085913" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoans" xlink:type="extended" xlink:title="995210401 - Disclosure - Loans and Allowance for Credit Losses on Loans" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansTextBlock" xlink:label="osbc_LoansTextBlock_639216265578087793" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="osbc_LoansTextBlock_639216265578087793" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureOtherRealEstateOwned" xlink:type="extended" xlink:title="995210501 - Disclosure - Other Real Estate Owned" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAbstract" xlink:label="us-gaap_RealEstateAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateOwnedTextBlock" xlink:label="us-gaap_RealEstateOwnedTextBlock_639216265578089629" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="us-gaap_RealEstateOwnedTextBlock_639216265578089629" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDeposits" xlink:type="extended" xlink:title="995210601 - Disclosure - Deposits" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsByTypeAbstract" xlink:label="us-gaap_DepositsByTypeAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositLiabilitiesDisclosuresTextBlock" xlink:label="us-gaap_DepositLiabilitiesDisclosuresTextBlock_639216265578091758" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_DepositLiabilitiesDisclosuresTextBlock_639216265578091758" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBorrowings" xlink:type="extended" xlink:title="995210701 - Disclosure - Borrowings" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock_639216265578092427" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureTextBlock_639216265578092427" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureJuniorSubordinatedDebentures" xlink:type="extended" xlink:title="995210801 - Disclosure - Junior Subordinated Debentures" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubordinatedBorrowingsAbstract" xlink:label="us-gaap_SubordinatedBorrowingsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubordinatedBorrowingsDisclosureTextBlock" xlink:label="us-gaap_SubordinatedBorrowingsDisclosureTextBlock_639216265578092427" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubordinatedBorrowingsAbstract" xlink:to="us-gaap_SubordinatedBorrowingsDisclosureTextBlock_639216265578092427" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEquityCompensationPlans" xlink:type="extended" xlink:title="995210901 - Disclosure - Equity Compensation Plans" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_639216265578092427" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_639216265578092427" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEarningsPerShare" xlink:type="extended" xlink:title="995211001 - Disclosure - Earnings Per Share" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="us-gaap_EarningsPerShareTextBlock_639216265578099204" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareTextBlock_639216265578099204" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMatters" xlink:type="extended" xlink:title="995211101 - Disclosure - Regulatory &amp; Capital Matters" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BankingAndThriftInterestAbstract" xlink:label="us-gaap_BankingAndThriftInterestAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:label="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_639216265578101304" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BankingAndThriftInterestAbstract" xlink:to="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_639216265578101304" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurements" xlink:type="extended" xlink:title="995211201 - Disclosure - Fair Value Measurements" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="us-gaap_FairValueDisclosuresTextBlock_639216265578103557" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresTextBlock_639216265578103557" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValuesOfFinancialInstruments" xlink:type="extended" xlink:title="995211301 - Disclosure - Fair Values of Financial Instruments" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" xlink:label="osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValuesOfFinancialInstrumentsDisclosureTextBlock" xlink:label="osbc_FairValuesOfFinancialInstrumentsDisclosureTextBlock_639216265578105924" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" xlink:to="osbc_FairValuesOfFinancialInstrumentsDisclosureTextBlock_639216265578105924" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRisk" xlink:type="extended" xlink:title="995211401 - Disclosure - Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock_639216265578107975" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock_639216265578107975" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSegmentInformation" xlink:type="extended" xlink:title="995211501 - Disclosure - Segment Information" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_639216265578111232" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_639216265578111232" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBasisOfPresentationAndChangesInSignificantAccountingPoliciesPolicies" xlink:type="extended" xlink:title="99920102 - Disclosure - Basis of Presentation and Changes in Significant Accounting Policies (Policies)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_639216265578112561" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_639216265578112561" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventsPolicyPolicyTextBlock" xlink:label="us-gaap_SubsequentEventsPolicyPolicyTextBlock_639216265578112561" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_SubsequentEventsPolicyPolicyTextBlock_639216265578112561" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureAcquisitionTables" xlink:type="extended" xlink:title="99930203 - Disclosure - Acquisition (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578112561" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578112561" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_639216265578112561" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578112561" xlink:to="us-gaap_BusinessAcquisitionAxis_639216265578112561" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578112561" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis_639216265578112561" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578112561" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BancorpFinancialMember" xlink:label="osbc_BancorpFinancialMember_639216265578117731" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578112561" xlink:to="osbc_BancorpFinancialMember_639216265578117731" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems_639216265578118899" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578112561" xlink:to="us-gaap_BusinessAcquisitionLineItems_639216265578118899" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_639216265578119364" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578118899" xlink:to="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_639216265578119364" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfFinancingReceivablesAcquiredNotAccountedForAsDebtSecuritiesTableTextBlock" xlink:label="osbc_ScheduleOfFinancingReceivablesAcquiredNotAccountedForAsDebtSecuritiesTableTextBlock_639216265578119364" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578118899" xlink:to="osbc_ScheduleOfFinancingReceivablesAcquiredNotAccountedForAsDebtSecuritiesTableTextBlock_639216265578119364" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSecuritiesTables" xlink:type="extended" xlink:title="99930303 - Disclosure - Securities (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfAvailableForSaleSecuritiesAndHeldToMaturitySecuritiesReconciliationTableTextBlock" xlink:label="osbc_ScheduleOfAvailableForSaleSecuritiesAndHeldToMaturitySecuritiesReconciliationTableTextBlock_639216265578119364" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:to="osbc_ScheduleOfAvailableForSaleSecuritiesAndHeldToMaturitySecuritiesReconciliationTableTextBlock_639216265578119364" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock" xlink:label="us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock_639216265578119364" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:to="us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock_639216265578119364" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfUnrealizedLossOnInvestmentsByCategoriesAndLengthOfTimeTableTextBlock" xlink:label="osbc_ScheduleOfUnrealizedLossOnInvestmentsByCategoriesAndLengthOfTimeTableTextBlock_639216265578146279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:to="osbc_ScheduleOfUnrealizedLossOnInvestmentsByCategoriesAndLengthOfTimeTableTextBlock_639216265578146279" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansTables" xlink:type="extended" xlink:title="99930403 - Disclosure - Loans and Allowance for Credit Losses on Loans (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock" xlink:label="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock_639216265578147801" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock" xlink:label="us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock_639216265578147801" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfCollateralDependentLoansAndRelatedAllowanceTableTextBlock" xlink:label="osbc_ScheduleOfCollateralDependentLoansAndRelatedAllowanceTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="osbc_ScheduleOfCollateralDependentLoansAndRelatedAllowanceTableTextBlock_639216265578147801" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PastDueFinancingReceivablesTableTextBlock" xlink:label="us-gaap_PastDueFinancingReceivablesTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_PastDueFinancingReceivablesTableTextBlock_639216265578147801" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivablesNonAccrualStatusTableTextBlock" xlink:label="us-gaap_ScheduleOfFinancingReceivablesNonAccrualStatusTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFinancingReceivablesNonAccrualStatusTableTextBlock_639216265578147801" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock" xlink:label="us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock_639216265578147801" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableGrossChargeOffsActivityTableTextBlock" xlink:label="osbc_FinancingReceivableGrossChargeOffsActivityTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="osbc_FinancingReceivableGrossChargeOffsActivityTableTextBlock_639216265578147801" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableModifiedTableTextBlock" xlink:label="osbc_FinancingReceivableModifiedTableTextBlock_639216265578147801" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="osbc_FinancingReceivableModifiedTableTextBlock_639216265578147801" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureOtherRealEstateOwnedTables" xlink:type="extended" xlink:title="99930503 - Disclosure - Other Real Estate Owned (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAbstract" xlink:label="us-gaap_RealEstateAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateAcquiredThroughForeclosureRollForwardTableTextBlock" xlink:label="osbc_RealEstateAcquiredThroughForeclosureRollForwardTableTextBlock_639216265578154455" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="osbc_RealEstateAcquiredThroughForeclosureRollForwardTableTextBlock_639216265578154455" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherRealEstateValuationAllowanceRollForwardTableTextBlock" xlink:label="osbc_OtherRealEstateValuationAllowanceRollForwardTableTextBlock_639216265578154999" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="osbc_OtherRealEstateValuationAllowanceRollForwardTableTextBlock_639216265578154999" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherRealEstateExpensesRelatedToForeclosedAssetsTableTextBlock" xlink:label="osbc_OtherRealEstateExpensesRelatedToForeclosedAssetsTableTextBlock_639216265578155917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="osbc_OtherRealEstateExpensesRelatedToForeclosedAssetsTableTextBlock_639216265578155917" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDepositsTables" xlink:type="extended" xlink:title="99930603 - Disclosure - Deposits (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsByTypeAbstract" xlink:label="us-gaap_DepositsByTypeAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfDepositsTableTextBlock" xlink:label="osbc_ScheduleOfDepositsTableTextBlock_639216265578158180" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="osbc_ScheduleOfDepositsTableTextBlock_639216265578158180" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBorrowingsTables" xlink:type="extended" xlink:title="99930703 - Disclosure - Borrowings (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock_639216265578158667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_ScheduleOfDebtInstrumentsTextBlock_639216265578158667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEquityCompensationPlansTables" xlink:type="extended" xlink:title="99930903 - Disclosure - Equity Compensation Plans (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock_639216265578158667" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock_639216265578158667" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEarningsPerShareTables" xlink:type="extended" xlink:title="99931003 - Disclosure - Earnings Per Share (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_639216265578163902" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_639216265578163902" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersTables" xlink:type="extended" xlink:title="99931103 - Disclosure - Regulatory &amp; Capital Matters (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BankingAndThriftInterestAbstract" xlink:label="us-gaap_BankingAndThriftInterestAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:label="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_639216265578164577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BankingAndThriftInterestAbstract" xlink:to="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_639216265578164577" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsTables" xlink:type="extended" xlink:title="99931203 - Disclosure - Fair Value Measurements (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_639216265578164577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_639216265578164577" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock" xlink:label="osbc_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock_639216265578164577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="osbc_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock_639216265578164577" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_639216265578164577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_639216265578164577" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock" xlink:label="us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock_639216265578164577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock_639216265578164577" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValuesOfFinancialInstrumentsTables" xlink:type="extended" xlink:title="99931303 - Disclosure - Fair Values of Financial Instruments (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" xlink:label="osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByBalanceSheetGroupingTextBlock" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTextBlock_639216265578171794" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" xlink:to="us-gaap_FairValueByBalanceSheetGroupingTextBlock_639216265578171794" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskTables" xlink:type="extended" xlink:title="99931403 - Disclosure - Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk (Tables)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_639216265578174741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_639216265578174741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfContractualCommitmentsDueToLettersOfCreditTableTextBlock" xlink:label="osbc_ScheduleOfContractualCommitmentsDueToLettersOfCreditTableTextBlock_639216265578175504" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="osbc_ScheduleOfContractualCommitmentsDueToLettersOfCreditTableTextBlock_639216265578175504" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBasisOfPresentationAndChangesInSignificantAccountingPoliciesDetails" xlink:type="extended" xlink:title="99940101 - Disclosure - Basis of Presentation and Changes in Significant Accounting Policies (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableTable" xlink:label="us-gaap_DividendsPayableTable_639216265578178358" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_DividendsPayableTable_639216265578178358" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis_639216265578179199" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableTable_639216265578178358" xlink:to="us-gaap_SubsequentEventTypeAxis_639216265578179199" order="1" use="optional" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain_639216265578180055" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeAxis_639216265578179199" xlink:to="us-gaap_SubsequentEventTypeDomain_639216265578180055" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember_639216265578180736" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeDomain_639216265578180055" xlink:to="us-gaap_SubsequentEventMember_639216265578180736" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsAxis" xlink:label="us-gaap_DividendsAxis_639216265578181819" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableTable_639216265578178358" xlink:to="us-gaap_DividendsAxis_639216265578181819" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain" xlink:label="us-gaap_DividendsDomain_639216265578182591" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsAxis_639216265578181819" xlink:to="us-gaap_DividendsDomain_639216265578182591" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_O2026Q3DividendsMember" xlink:label="osbc_O2026Q3DividendsMember_639216265578183333" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsDomain_639216265578182591" xlink:to="osbc_O2026Q3DividendsMember_639216265578183333" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableLineItems" xlink:label="us-gaap_DividendsPayableLineItems_639216265578184661" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableTable_639216265578178358" xlink:to="us-gaap_DividendsPayableLineItems_639216265578184661" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount_639216265578185819" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DebtInstrumentFaceAmount_639216265578185819" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_639216265578186621" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_639216265578186621" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_639216265578187561" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_639216265578187561" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration" xlink:label="us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration_639216265578188626" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_639216265578187561" xlink:to="us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration_639216265578188626" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableDateDeclaredDayMonthAndYear" xlink:label="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_639216265578189518" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_639216265578189518" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableAmountPerShare" xlink:label="us-gaap_DividendsPayableAmountPerShare_639216265578190623" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DividendsPayableAmountPerShare_639216265578190623" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear" xlink:label="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_639216265578191628" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DividendPayableDateToBePaidDayMonthAndYear_639216265578191628" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear" xlink:label="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_639216265578192689" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_639216265578192689" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfDividends" xlink:label="us-gaap_PaymentsOfDividends_639216265578193498" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DividendsPayableLineItems_639216265578184661" xlink:to="us-gaap_PaymentsOfDividends_639216265578193498" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureAcquisitionDetails" xlink:type="extended" xlink:title="99940201 - Disclosure - Acquisition (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract_4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578194663" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract_4" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578194663" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_639216265578194663" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578194663" xlink:to="us-gaap_BusinessAcquisitionAxis_639216265578194663" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578194663" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis_639216265578194663" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578194663" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BancorpFinancialMember" xlink:label="osbc_BancorpFinancialMember_639216265578194663" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578194663" xlink:to="osbc_BancorpFinancialMember_639216265578194663" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems_639216265578194663" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578194663" xlink:to="us-gaap_BusinessAcquisitionLineItems_639216265578194663" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_639216265578194663" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_639216265578194663" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_639216265578200798" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_639216265578200798" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_639216265578202104" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_639216265578202104" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedLiabilityAssumedTotalDeposit" xlink:label="osbc_BusinessCombinationRecognizedLiabilityAssumedTotalDeposit_639216265578203050" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="osbc_BusinessCombinationRecognizedLiabilityAssumedTotalDeposit_639216265578203050" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationEquityInterestIssuedOrIssuableNumberOfSharesForEachShare" xlink:label="osbc_BusinessCombinationEquityInterestIssuedOrIssuableNumberOfSharesForEachShare_639216265578203666" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="osbc_BusinessCombinationEquityInterestIssuedOrIssuableNumberOfSharesForEachShare_639216265578203666" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationCashConsiderationPerShare" xlink:label="osbc_BusinessCombinationCashConsiderationPerShare_639216265578204527" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="osbc_BusinessCombinationCashConsiderationPerShare_639216265578204527" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_639216265578205456" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1_639216265578205456" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_639216265578206281" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_639216265578206281" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_639216265578207552" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross_639216265578207552" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill_639216265578208466" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_Goodwill_639216265578208466" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount" xlink:label="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_639216265578209702" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount_639216265578209702" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationAcquisitionRelatedCostsExcludingItem" xlink:label="osbc_BusinessCombinationAcquisitionRelatedCostsExcludingItem_639216265578210679" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578194663" xlink:to="osbc_BusinessCombinationAcquisitionRelatedCostsExcludingItem_639216265578210679" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureAcquisitionBancorpFinancialAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="extended" xlink:title="99940202 - Disclosure - Acquisition - Bancorp Financial assets acquired and liabilities assumed (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract_1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578214424" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract_1" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578214424" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_639216265578215248" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578214424" xlink:to="us-gaap_BusinessAcquisitionAxis_639216265578215248" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578215925" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis_639216265578215248" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578215925" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BancorpFinancialMember" xlink:label="osbc_BancorpFinancialMember_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578215925" xlink:to="osbc_BancorpFinancialMember_639216265578216920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578214424" xlink:to="us-gaap_BusinessAcquisitionLineItems_639216265578216920" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_639216265578216920" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_639216265578216920" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsFhlbcStock" xlink:label="osbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsFhlbcStock_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="osbc_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsFhlbcStock_639216265578216920" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_639216265578216920" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_639216265578216920" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_639216265578216920" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_639216265578222135" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_639216265578222135" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance" xlink:label="osbc_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance_639216265578222962" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="osbc_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance_639216265578222962" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_639216265578223977" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_639216265578223977" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_639216265578225028" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_639216265578225028" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_639216265578226281" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_639216265578226281" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedLiabilityAssumedNonInterestBearingDemandDeposit" xlink:label="osbc_BusinessCombinationRecognizedLiabilityAssumedNonInterestBearingDemandDeposit_639216265578228357" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="osbc_BusinessCombinationRecognizedLiabilityAssumedNonInterestBearingDemandDeposit_639216265578228357" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedLiabilityAssumedInterestBearingDeposit" xlink:label="osbc_BusinessCombinationRecognizedLiabilityAssumedInterestBearingDeposit_639216265578229035" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="osbc_BusinessCombinationRecognizedLiabilityAssumedInterestBearingDeposit_639216265578229035" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedLiabilityAssumedTotalDeposit" xlink:label="osbc_BusinessCombinationRecognizedLiabilityAssumedTotalDeposit_639216265578230193" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="osbc_BusinessCombinationRecognizedLiabilityAssumedTotalDeposit_639216265578230193" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationRecognizedLiabilityAssumedShortTermBorrowings" xlink:label="osbc_BusinessCombinationRecognizedLiabilityAssumedShortTermBorrowings_639216265578231076" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="osbc_BusinessCombinationRecognizedLiabilityAssumedShortTermBorrowings_639216265578231076" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_639216265578232050" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_639216265578232050" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_639216265578233180" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_639216265578233180" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_639216265578234371" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_639216265578227359" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_639216265578234371" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_639216265578235707" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross_639216265578235707" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_639216265578236744" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_639216265578236744" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_639216265578238039" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1_639216265578238039" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_639216265578239258" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_639216265578239258" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill_639216265578240740" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578216920" xlink:to="us-gaap_Goodwill_639216265578240740" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureAcquisitionBancorpFinancialScheduleOfPurchasePriceOfLoansAtAcquisitionDetails" xlink:type="extended" xlink:title="99940203 - Disclosure - Acquisition - Bancorp Financial - Schedule of Purchase price of loans at acquisition (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract_2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578240740" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract_2" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578240740" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis_639216265578240740" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578240740" xlink:to="us-gaap_BusinessAcquisitionAxis_639216265578240740" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578240740" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis_639216265578240740" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578240740" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BancorpFinancialMember" xlink:label="osbc_BancorpFinancialMember_639216265578245946" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain_639216265578240740" xlink:to="osbc_BancorpFinancialMember_639216265578245946" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems_639216265578246637" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_639216265578240740" xlink:to="us-gaap_BusinessAcquisitionLineItems_639216265578246637" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationAcquiredReceivablesAbstract" xlink:label="us-gaap_BusinessCombinationAcquiredReceivablesAbstract_639216265578247576" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems_639216265578246637" xlink:to="us-gaap_BusinessCombinationAcquiredReceivablesAbstract_639216265578247576" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationGrossContractualAmount" xlink:label="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationGrossContractualAmount_639216265578248442" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationAcquiredReceivablesAbstract_639216265578247576" xlink:to="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationGrossContractualAmount_639216265578248442" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLoss" xlink:label="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLoss_639216265578249386" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationAcquiredReceivablesAbstract_639216265578247576" xlink:to="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLoss_639216265578249386" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationNonCreditPremium" xlink:label="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationNonCreditPremium_639216265578250510" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationAcquiredReceivablesAbstract_639216265578247576" xlink:to="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationNonCreditPremium_639216265578250510" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationFairValue" xlink:label="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationFairValue_639216265578251489" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationAcquiredReceivablesAbstract_639216265578247576" xlink:to="osbc_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationFairValue_639216265578251489" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSecuritiesAmortizedCostAndFairValueDetails" xlink:type="extended" xlink:title="99940301 - Disclosure - Securities - Amortized Cost and Fair Value (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract_635511257075502413" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsTable" xlink:label="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract_635511257075502413" xlink:to="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578253778" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578253778" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578253778" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578253778" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="us-gaap_USTreasurySecuritiesMember_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_USTreasurySecuritiesMember_639216265578253778" order="1" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember" xlink:label="us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_639216265578253778" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember" xlink:label="us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember_639216265578253778" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578253778" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578253778" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedMortgageObligationsMember" xlink:label="us-gaap_CollateralizedMortgageObligationsMember_639216265578258977" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_CollateralizedMortgageObligationsMember_639216265578258977" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_639216265578260065" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_AssetBackedSecuritiesMember_639216265578260065" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedLoanObligationsMember" xlink:label="us-gaap_CollateralizedLoanObligationsMember_639216265578260918" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_CollateralizedLoanObligationsMember_639216265578260918" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember" xlink:label="osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember_639216265578261291" order="8" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember" xlink:label="us-gaap_EquitySecuritiesMember_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578253778" xlink:to="us-gaap_EquitySecuritiesMember_639216265578261291" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems" xlink:label="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578253778" xlink:to="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578261291" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578261291" xlink:to="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578261291" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_639216265578261291" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_639216265578261291" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_639216265578261291" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578267179" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578267179" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/positiveTerseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedInvestmentIncomeReceivable" xlink:label="us-gaap_AccruedInvestmentIncomeReceivable_639216265578268328" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" xlink:to="us-gaap_AccruedInvestmentIncomeReceivable_639216265578268328" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStockAbstract" xlink:label="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStockAbstract_639216265578269590" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract_639216265578261291" xlink:to="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStockAbstract_639216265578269590" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankStock" xlink:label="us-gaap_FederalHomeLoanBankStock_639216265578270701" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStockAbstract_639216265578269590" xlink:to="us-gaap_FederalHomeLoanBankStock_639216265578270701" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalReserveBankStock" xlink:label="us-gaap_FederalReserveBankStock_639216265578271869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStockAbstract_639216265578269590" xlink:to="us-gaap_FederalReserveBankStock_639216265578271869" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketableSecuritiesAbstract" xlink:label="us-gaap_MarketableSecuritiesAbstract_639216265578273030" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578261291" xlink:to="us-gaap_MarketableSecuritiesAbstract_639216265578273030" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NumberOfSecuritiesIssuedFromOriginators" xlink:label="osbc_NumberOfSecuritiesIssuedFromOriginators_639216265578273989" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MarketableSecuritiesAbstract_639216265578273030" xlink:to="osbc_NumberOfSecuritiesIssuedFromOriginators_639216265578273989" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NumberOfOriginatorsThatCompanyHasInvestedOverSpecifiedPercentageOfItsStockholdersEquity" xlink:label="osbc_NumberOfOriginatorsThatCompanyHasInvestedOverSpecifiedPercentageOfItsStockholdersEquity_639216265578275456" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MarketableSecuritiesAbstract_639216265578273030" xlink:to="osbc_NumberOfOriginatorsThatCompanyHasInvestedOverSpecifiedPercentageOfItsStockholdersEquity_639216265578275456" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MinimumPercentageOfSecuritiesInvestmentFromOriginators" xlink:label="osbc_MinimumPercentageOfSecuritiesInvestmentFromOriginators_639216265578276608" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MarketableSecuritiesAbstract_639216265578273030" xlink:to="osbc_MinimumPercentageOfSecuritiesInvestmentFromOriginators_639216265578276608" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt" xlink:label="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_639216265578277565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578261291" xlink:to="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_639216265578277565" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleRestricted" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleRestricted_639216265578278945" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578261291" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleRestricted_639216265578278945" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSecuritiesContractualMaturitiesDetails" xlink:type="extended" xlink:title="99940302 - Disclosure - Securities - Contractual Maturities (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract_635429230408461590" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsTable" xlink:label="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578283296" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract_635429230408461590" xlink:to="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578283296" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578284265" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578283296" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578284265" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578285047" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578284265" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578285047" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageBackedAndCollateralizedMortgageObligationsMember" xlink:label="osbc_MortgageBackedAndCollateralizedMortgageObligationsMember_639216265578286089" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578285047" xlink:to="osbc_MortgageBackedAndCollateralizedMortgageObligationsMember_639216265578286089" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_639216265578286577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578285047" xlink:to="us-gaap_AssetBackedSecuritiesMember_639216265578286577" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedLoanObligationsMember" xlink:label="us-gaap_CollateralizedLoanObligationsMember_639216265578287430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578285047" xlink:to="us-gaap_CollateralizedLoanObligationsMember_639216265578287430" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember" xlink:label="us-gaap_EquitySecuritiesMember_639216265578288451" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578285047" xlink:to="us-gaap_EquitySecuritiesMember_639216265578288451" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems" xlink:label="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578289290" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578283296" xlink:to="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578289290" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578289290" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_639216265578291298" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_639216265578291298" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_639216265578291298" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_639216265578291298" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateAmortizedCostBasis" xlink:label="osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateAmortizedCostBasis_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateAmortizedCostBasis_639216265578291298" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_639216265578291298" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_639216265578290264" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578291298" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract" xlink:label="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578289290" xlink:to="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCostWeightedAverageYield" xlink:label="osbc_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCostWeightedAverageYield_639216265578297219" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCostWeightedAverageYield_639216265578297219" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCostWeightedAverageYield" xlink:label="osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCostWeightedAverageYield_639216265578298084" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCostWeightedAverageYield_639216265578298084" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCostWeightedAverageYield" xlink:label="osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCostWeightedAverageYield_639216265578298618" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCostWeightedAverageYield_639216265578298618" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCostWeightedAverageYield" xlink:label="osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCostWeightedAverageYield_639216265578299455" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCostWeightedAverageYield_639216265578299455" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateWeightedAverageYield" xlink:label="osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateWeightedAverageYield_639216265578300250" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateWeightedAverageYield_639216265578300250" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateWeightedAverageYield" xlink:label="osbc_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateWeightedAverageYield_639216265578301084" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateWeightedAverageYield_639216265578301084" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesWeightedAverageYield" xlink:label="osbc_AvailableForSaleSecuritiesWeightedAverageYield_639216265578301894" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostWeightedAverageYieldAbstract_639216265578291298" xlink:to="osbc_AvailableForSaleSecuritiesWeightedAverageYield_639216265578301894" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578289290" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_639216265578304025" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_639216265578304025" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_639216265578305235" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_639216265578305235" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_639216265578306565" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_639216265578306565" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_639216265578307990" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_639216265578307990" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateFairValue" xlink:label="osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateFairValue_639216265578309325" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="osbc_AvailableForSaleDebtMaturitiesBeforeSecuritiesWithoutSingleMaturityDateFairValue_639216265578309325" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_639216265578309813" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_639216265578309813" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578309813" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_639216265578302911" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578309813" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSecuritiesUnrealizedLossPositionsDetails" xlink:type="extended" xlink:title="99940303 - Disclosure - Securities - Unrealized Loss Positions (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsTable" xlink:label="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578309813" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract" xlink:to="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578309813" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578315050" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578309813" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578315050" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578315050" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="us-gaap_USTreasurySecuritiesMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="us-gaap_USTreasurySecuritiesMember_639216265578316197" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember" xlink:label="us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_639216265578316197" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember" xlink:label="osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember_639216265578316197" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578316197" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedMortgageObligationsMember" xlink:label="us-gaap_CollateralizedMortgageObligationsMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="us-gaap_CollateralizedMortgageObligationsMember_639216265578316197" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="us-gaap_AssetBackedSecuritiesMember_639216265578316197" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedLoanObligationsMember" xlink:label="us-gaap_CollateralizedLoanObligationsMember_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578315665" xlink:to="us-gaap_CollateralizedLoanObligationsMember_639216265578316197" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems" xlink:label="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578316197" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsTable_639216265578309813" xlink:to="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578316197" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_639216265578322174" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578316197" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_639216265578322174" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionQualitativeDisclosureAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionQualitativeDisclosureAbstract_639216265578323118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_639216265578322174" xlink:to="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionQualitativeDisclosureAbstract_639216265578323118" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesInUnrealizedLossPositionLessThan12MonthsQualitativeDisclosureNumberOfPositions" xlink:label="osbc_AvailableForSaleSecuritiesInUnrealizedLossPositionLessThan12MonthsQualitativeDisclosureNumberOfPositions_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionQualitativeDisclosureAbstract_639216265578323118" xlink:to="osbc_AvailableForSaleSecuritiesInUnrealizedLossPositionLessThan12MonthsQualitativeDisclosureNumberOfPositions_639216265578323869" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AvailableForSaleSecuritiesInUnrealizedLossPositions12MonthsOrLongerQualitativeDisclosureNumberOfPositions" xlink:label="osbc_AvailableForSaleSecuritiesInUnrealizedLossPositions12MonthsOrLongerQualitativeDisclosureNumberOfPositions_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionQualitativeDisclosureAbstract_639216265578323118" xlink:to="osbc_AvailableForSaleSecuritiesInUnrealizedLossPositions12MonthsOrLongerQualitativeDisclosureNumberOfPositions_639216265578323869" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionQualitativeDisclosureAbstract_639216265578323118" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_639216265578323869" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_639216265578322174" xlink:to="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_639216265578323869" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_639216265578323869" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_639216265578323869" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_639216265578323869" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_639216265578323869" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_639216265578323869" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_639216265578323869" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_639216265578323869" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract" xlink:label="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_639216265578329364" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_639216265578322174" xlink:to="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_639216265578329364" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_639216265578330301" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_639216265578329364" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_639216265578330301" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_639216265578330301" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_639216265578329364" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_639216265578330301" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_639216265578330301" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract_639216265578329364" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_639216265578330301" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest_639216265578330301" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578316197" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest_639216265578330301" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InvestmentPortfolioEffectiveDuration" xlink:label="osbc_InvestmentPortfolioEffectiveDuration_639216265578330301" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentHoldingsLineItems_639216265578316197" xlink:to="osbc_InvestmentPortfolioEffectiveDuration_639216265578330301" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansMajorClassificationsDetails" xlink:type="extended" xlink:title="99940401 - Disclosure - Loans and Allowance for Credit Losses on Loans - Major Classifications (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:label="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578336483" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578336483" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578336483" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578336483" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578336483" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578336483" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578336483" order="3" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578336483" order="4" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578336483" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="us-gaap_ConstructionMember_639216265578336483" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateInvestorMember" xlink:label="osbc_RealEstateInvestorMember_639216265578341697" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_RealEstateInvestorMember_639216265578341697" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnerOccupiedMember" xlink:label="osbc_RealEstateOwnerOccupiedMember_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_RealEstateOwnerOccupiedMember_639216265578341940" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_MultiFamilyLoanMember_639216265578341940" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="us-gaap_HomeEquityMember_639216265578341940" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578341940" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_Other2Member" xlink:label="osbc_Other2Member_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578336483" xlink:to="osbc_Other2Member_639216265578341940" order="11" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:label="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578336483" xlink:to="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578341940" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578341940" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578341940" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265578341940" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578341940" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265578341940" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss_639216265578347928" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578341940" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss_639216265578347928" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="5" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansMajorClassificationsLoanConcentrationsDetails" xlink:type="extended" xlink:title="99940402 - Disclosure - Loans and Allowance for Credit Losses on Loans - Major Classifications - Loan Concentrations (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract_635664310358476876" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:label="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578347928" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract_635664310358476876" xlink:to="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578347928" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578347928" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578347928" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578347928" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578347928" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578347928" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578347928" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstatePortfolioSegmentMember" xlink:label="osbc_RealEstatePortfolioSegmentMember_639216265578347928" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578347928" xlink:to="osbc_RealEstatePortfolioSegmentMember_639216265578347928" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_639216265578347928" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578347928" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis_639216265578347928" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_639216265578353163" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis_639216265578347928" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain_639216265578353163" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsReceivableMember" xlink:label="us-gaap_AccountsReceivableMember_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain_639216265578353163" xlink:to="us-gaap_AccountsReceivableMember_639216265578353421" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578347928" xlink:to="us-gaap_ConcentrationRiskByTypeAxis_639216265578353421" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskByTypeAxis_639216265578353421" xlink:to="us-gaap_ConcentrationRiskTypeDomain_639216265578353421" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskTypeDomain_639216265578353421" xlink:to="us-gaap_CustomerConcentrationRiskMember_639216265578353421" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:label="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578347928" xlink:to="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578353421" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseAccruedInterest" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseAccruedInterest_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578353421" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseAccruedInterest_639216265578353421" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansAndLeasesReceivableAsPercentageOfAggregatePortfolio" xlink:label="osbc_LoansAndLeasesReceivableAsPercentageOfAggregatePortfolio_639216265578353421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578353421" xlink:to="osbc_LoansAndLeasesReceivableAsPercentageOfAggregatePortfolio_639216265578353421" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansDetails" xlink:type="extended" xlink:title="99940403 - Disclosure - Loans and Allowance for Credit Losses on Loans (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AllowanceForLoanLossesDisclosureAbstract" xlink:label="osbc_AllowanceForLoanLossesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable" xlink:label="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_AllowanceForLoanLossesDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_639216265578359388" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_639216265578359388" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_639216265578359388" order="1" use="optional" priority="6" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_639216265578359388" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_639216265578359388" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnfundedLoanCommitmentMember" xlink:label="us-gaap_UnfundedLoanCommitmentMember_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_639216265578359388" xlink:to="us-gaap_UnfundedLoanCommitmentMember_639216265578359388" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_639216265578359388" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578359388" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578359388" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578359388" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578359388" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578364859" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578364859" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578364859" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="us-gaap_ConstructionMember_639216265578364859" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateInvestorMember" xlink:label="osbc_RealEstateInvestorMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="osbc_RealEstateInvestorMember_639216265578364859" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnerOccupiedMember" xlink:label="osbc_RealEstateOwnerOccupiedMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="osbc_RealEstateOwnerOccupiedMember_639216265578364859" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="osbc_MultiFamilyLoanMember_639216265578364859" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="us-gaap_HomeEquityMember_639216265578364859" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578364859" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578359388" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578364859" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="us-gaap_BalanceSheetLocationAxis_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_639216265578359388" xlink:to="us-gaap_BalanceSheetLocationAxis_639216265578364859" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="us-gaap_BalanceSheetLocationDomain_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BalanceSheetLocationAxis_639216265578364859" xlink:to="us-gaap_BalanceSheetLocationDomain_639216265578364859" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilitiesMember" xlink:label="us-gaap_OtherLiabilitiesMember_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BalanceSheetLocationDomain_639216265578364859" xlink:to="us-gaap_OtherLiabilitiesMember_639216265578364859" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_639216265578359388" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_639216265578364859" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllowanceForLoanAndLeaseLossesRollForward" xlink:label="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_639216265578364859" xlink:to="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265578375917" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestCreditLossExpenseReversal" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestCreditLossExpenseReversal_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestCreditLossExpenseReversal_639216265578375917" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff_639216265578375917" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossRecovery" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossRecovery_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossRecovery_639216265578375917" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_6392162655783759171" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_6392162655783759171" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OffBalanceSheetCreditLossLiability" xlink:label="us-gaap_OffBalanceSheetCreditLossLiability_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="us-gaap_OffBalanceSheetCreditLossLiability_639216265578375917" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_639216265578375917" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual_639216265578375917" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAllowanceForCreditLossIncrementalWriteoff" xlink:label="osbc_FinancingReceivableAllowanceForCreditLossIncrementalWriteoff_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AllowanceForLoanAndLeaseLossesRollForward_639216265578364859" xlink:to="osbc_FinancingReceivableAllowanceForCreditLossIncrementalWriteoff_639216265578375917" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansCollateralDependentLoansDetails" xlink:type="extended" xlink:title="99940404 - Disclosure - Loans and Allowance for Credit Losses on Loans - Collateral dependent loans (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:label="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578375917" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578375917" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578375917" order="1" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578375917" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578375917" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578375917" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578375917" order="3" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578375917" order="4" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="us-gaap_ConstructionMember_639216265578375917" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateInvestorMember" xlink:label="osbc_RealEstateInvestorMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="osbc_RealEstateInvestorMember_639216265578375917" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnerOccupiedMember" xlink:label="osbc_RealEstateOwnerOccupiedMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="osbc_RealEstateOwnerOccupiedMember_639216265578375917" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="osbc_MultiFamilyLoanMember_639216265578375917" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="us-gaap_HomeEquityMember_639216265578375917" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578375917" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578375917" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578375917" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralAxis" xlink:label="us-gaap_CollateralAxis_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578375917" xlink:to="us-gaap_CollateralAxis_639216265578375917" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralDomain" xlink:label="us-gaap_CollateralDomain_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollateralAxis_639216265578375917" xlink:to="us-gaap_CollateralDomain_639216265578375917" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateMember" xlink:label="us-gaap_RealEstateMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollateralDomain_639216265578375917" xlink:to="us-gaap_RealEstateMember_639216265578375917" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceReceivablesMember" xlink:label="us-gaap_FinanceReceivablesMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollateralDomain_639216265578375917" xlink:to="us-gaap_FinanceReceivablesMember_639216265578375917" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquipmentMember" xlink:label="us-gaap_EquipmentMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollateralDomain_639216265578375917" xlink:to="us-gaap_EquipmentMember_639216265578375917" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember" xlink:label="us-gaap_EquitySecuritiesMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollateralDomain_639216265578375917" xlink:to="us-gaap_EquitySecuritiesMember_639216265578375917" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralPledgedMember" xlink:label="us-gaap_CollateralPledgedMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CollateralDomain_639216265578375917" xlink:to="us-gaap_CollateralPledgedMember_639216265578375917" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PledgedStatusAxis" xlink:label="us-gaap_PledgedStatusAxis_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578375917" xlink:to="us-gaap_PledgedStatusAxis_639216265578375917" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PledgedStatusDomain" xlink:label="us-gaap_PledgedStatusDomain_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PledgedStatusAxis_639216265578375917" xlink:to="us-gaap_PledgedStatusDomain_639216265578375917" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetPledgedAsCollateralWithoutRightMember" xlink:label="us-gaap_AssetPledgedAsCollateralWithoutRightMember_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PledgedStatusDomain_639216265578375917" xlink:to="us-gaap_AssetPledgedAsCollateralWithoutRightMember_639216265578375917" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:label="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_639216265578375917" xlink:to="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578375917" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578375917" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAfterAllowanceForCreditLoss_639216265578375917" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265578375917" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems_639216265578375917" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseAllowanceForCreditLossExcludingAccruedInterest_639216265578375917" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansAgingAnalysisDetails" xlink:type="extended" xlink:title="99940405 - Disclosure - Loans and Allowance for Credit Losses on Loans - Aging Analysis (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivablesPastDueTable" xlink:label="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578426151" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578426151" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578426151" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578426151" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578426151" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578426151" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578427512" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_ConstructionMember_639216265578427512" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateInvestorMember" xlink:label="osbc_RealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstateInvestorMember_639216265578427512" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnerOccupiedMember" xlink:label="osbc_RealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstateOwnerOccupiedMember_639216265578427512" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_MultiFamilyLoanMember_639216265578427512" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_HomeEquityMember_639216265578427512" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578427512" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578426151" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueAxis_639216265578427512" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueAxis_639216265578427512" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialAssetPastDueMember" xlink:label="us-gaap_FinancialAssetPastDueMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578427512" xlink:to="us-gaap_FinancialAssetPastDueMember_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivables30To59DaysPastDueMember" xlink:label="us-gaap_FinancingReceivables30To59DaysPastDueMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialAssetPastDueMember_639216265578427512" xlink:to="us-gaap_FinancingReceivables30To59DaysPastDueMember_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivables60To89DaysPastDueMember" xlink:label="us-gaap_FinancingReceivables60To89DaysPastDueMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialAssetPastDueMember_639216265578427512" xlink:to="us-gaap_FinancingReceivables60To89DaysPastDueMember_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember" xlink:label="us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialAssetPastDueMember_639216265578427512" xlink:to="us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialAssetNotPastDueMember" xlink:label="us-gaap_FinancialAssetNotPastDueMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578427512" xlink:to="us-gaap_FinancialAssetNotPastDueMember_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578426151" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseBeforeAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseBeforeAllowanceForCreditLoss_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseBeforeAllowanceForCreditLoss_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/positiveLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing" xlink:label="us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" xlink:to="us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansNonaccrualsDetails" xlink:type="extended" xlink:title="99940406 - Disclosure - Loans and Allowance for Credit Losses on Loans - Nonaccruals (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivablesPastDueTable" xlink:label="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578427512" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578427512" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" order="1" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578427512" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_ConstructionMember_639216265578427512" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateInvestorMember" xlink:label="osbc_RealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstateInvestorMember_639216265578427512" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnerOccupiedMember" xlink:label="osbc_RealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstateOwnerOccupiedMember_639216265578427512" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_MultiFamilyLoanMember_639216265578427512" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_HomeEquityMember_639216265578427512" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578427512" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable_639216265578427512" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseRecordedInvestmentNonaccrualStatus" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseRecordedInvestmentNonaccrualStatus_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseRecordedInvestmentNonaccrualStatus_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseNonaccrualNoAllowance" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseNonaccrualNoAllowance_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseNonaccrualNoAllowance_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseNonaccrualInterestIncome" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseNonaccrualInterestIncome_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseNonaccrualInterestIncome_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansCreditQualityDetails" xlink:type="extended" xlink:title="99940407 - Disclosure - Loans and Allowance for Credit Losses on Loans - Credit Quality (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable" xlink:label="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" order="1" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstatePortfolioSegmentMember" xlink:label="osbc_RealEstatePortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstatePortfolioSegmentMember_639216265578427512" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResidentialPortfolioSegmentMember" xlink:label="us-gaap_ResidentialPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_RealEstatePortfolioSegmentMember_639216265578427512" xlink:to="us-gaap_ResidentialPortfolioSegmentMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578427512" order="4" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" order="5" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_ConstructionMember_639216265578427512" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateInvestorMember" xlink:label="osbc_RealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstateInvestorMember_639216265578427512" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnerOccupiedMember" xlink:label="osbc_RealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_RealEstateOwnerOccupiedMember_639216265578427512" order="8" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_MultiFamilyLoanMember_639216265578427512" order="9" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_HomeEquityMember_639216265578427512" order="10" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578427512" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_639216265578427512" order="2" use="optional" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_639216265578427512" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NonRiskRatedLoansMember" xlink:label="osbc_NonRiskRatedLoansMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_639216265578427512" xlink:to="osbc_NonRiskRatedLoansMember_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentPerformanceStatusAxis" xlink:label="us-gaap_FinancialInstrumentPerformanceStatusAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_FinancialInstrumentPerformanceStatusAxis_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain" xlink:label="us-gaap_FinancialInstrumentPerformanceStatusDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentPerformanceStatusAxis_639216265578427512" xlink:to="us-gaap_FinancialInstrumentPerformanceStatusDomain_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformingFinancingReceivableMember" xlink:label="us-gaap_PerformingFinancingReceivableMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentPerformanceStatusDomain_639216265578427512" xlink:to="us-gaap_PerformingFinancingReceivableMember_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonperformingFinancingReceivableMember" xlink:label="us-gaap_NonperformingFinancingReceivableMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentPerformanceStatusDomain_639216265578427512" xlink:to="us-gaap_NonperformingFinancingReceivableMember_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InternalCreditAssessmentAxis" xlink:label="us-gaap_InternalCreditAssessmentAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_InternalCreditAssessmentAxis_639216265578427512" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InternalCreditAssessmentDomain" xlink:label="us-gaap_InternalCreditAssessmentDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InternalCreditAssessmentAxis_639216265578427512" xlink:to="us-gaap_InternalCreditAssessmentDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PassMember" xlink:label="us-gaap_PassMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InternalCreditAssessmentDomain_639216265578427512" xlink:to="us-gaap_PassMember_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SpecialMentionMember" xlink:label="us-gaap_SpecialMentionMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InternalCreditAssessmentDomain_639216265578427512" xlink:to="us-gaap_SpecialMentionMember_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubstandardMember" xlink:label="us-gaap_SubstandardMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InternalCreditAssessmentDomain_639216265578427512" xlink:to="us-gaap_SubstandardMember_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DoubtfulMember" xlink:label="us-gaap_DoubtfulMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InternalCreditAssessmentDomain_639216265578427512" xlink:to="us-gaap_DoubtfulMember_639216265578427512" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="srt_RangeAxis_639216265578427512" order="5" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="srt_RangeMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_639216265578427512" xlink:to="srt_RangeMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578427512" xlink:to="srt_MinimumMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeFiscalYear" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeFiscalYear_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeFiscalYear_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeFiscalYear" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeFiscalYear_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeFiscalYear_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeFiscalYear" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeFiscalYear_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeFiscalYear_639216265578427512" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeFiscalYear" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeFiscalYear_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeFiscalYear_639216265578427512" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_639216265578427512" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolving" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_639216265578427512" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan_639216265578427512" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestBeforeAllowanceForCreditLoss_639216265578427512" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OutstandingLoanCommitmentsThresholdForCreditQualityCategorizing" xlink:label="osbc_OutstandingLoanCommitmentsThresholdForCreditQualityCategorizing_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="osbc_OutstandingLoanCommitmentsThresholdForCreditQualityCategorizing_639216265578427512" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MortgageLoansInProcessOfForeclosureAmount" xlink:label="us-gaap_MortgageLoansInProcessOfForeclosureAmount_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossByOriginationYearAbstract_639216265578427512" xlink:to="us-gaap_MortgageLoansInProcessOfForeclosureAmount_639216265578427512" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansChargeOffsActivityByLoanTypeDetails" xlink:type="extended" xlink:title="99940408 - Disclosure - Loans and Allowance for Credit Losses on Loans - Charge-offs Activity by Loan Type (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract_2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable" xlink:label="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract_2" xlink:to="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" order="1" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578427512" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578427512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinanceLeasesPortfolioSegmentMember" xlink:label="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_FinanceLeasesPortfolioSegmentMember_639216265578427512" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578427512" order="3" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578427512" order="4" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_ConstructionMember_639216265578427512" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_HomeEquityMember_639216265578427512" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578427512" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578427512" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578427512" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_639216265578427512" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_639216265578427512" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_639216265578427512" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_639216265578427512" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_639216265578427512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_639216265578427512" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_639216265578507943" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_639216265578507943" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_639216265578508767" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_639216265578508767" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff" xlink:label="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff_639216265578509591" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems_639216265578427512" xlink:to="osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff_639216265578509591" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureLoansAndAllowanceForCreditLossesOnLoansLoanModificationsDetails" xlink:type="extended" xlink:title="99940409 - Disclosure - Loans and Allowance for Credit Losses on Loans - Loan Modifications (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LoansDisclosureAbstract" xlink:label="osbc_LoansDisclosureAbstract_1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable" xlink:label="us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_LoansDisclosureAbstract_1" xlink:to="us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_639216265578511712" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_639216265578511712" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578511712" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain" xlink:label="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentAxis_639216265578511712" xlink:to="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommercialPortfolioSegmentMember" xlink:label="us-gaap_CommercialPortfolioSegmentMember_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="us-gaap_CommercialPortfolioSegmentMember_639216265578511712" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateInvestorMember" xlink:label="osbc_CommercialRealEstateInvestorMember_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="osbc_CommercialRealEstateInvestorMember_639216265578511712" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialRealEstateOwnerOccupiedMember" xlink:label="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="osbc_CommercialRealEstateOwnerOccupiedMember_639216265578511712" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConstructionMember" xlink:label="us-gaap_ConstructionMember_639216265578511712" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="us-gaap_ConstructionMember_639216265578511712" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MultiFamilyLoanMember" xlink:label="osbc_MultiFamilyLoanMember_639216265578516956" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="osbc_MultiFamilyLoanMember_639216265578516956" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HomeEquityMember" xlink:label="us-gaap_HomeEquityMember_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="us-gaap_HomeEquityMember_639216265578517828" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_PowersportPortfolioSegmentMember" xlink:label="osbc_PowersportPortfolioSegmentMember_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="osbc_PowersportPortfolioSegmentMember_639216265578517828" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnallocatedFinancingReceivablesMember" xlink:label="us-gaap_UnallocatedFinancingReceivablesMember_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablePortfolioSegmentDomain_639216265578511712" xlink:to="us-gaap_UnallocatedFinancingReceivablesMember_639216265578517828" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoanRestructuringModificationAxis" xlink:label="us-gaap_LoanRestructuringModificationAxis_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_639216265578511712" xlink:to="us-gaap_LoanRestructuringModificationAxis_639216265578517828" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoanRestructuringModificationDomain" xlink:label="us-gaap_LoanRestructuringModificationDomain_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LoanRestructuringModificationAxis_639216265578517828" xlink:to="us-gaap_LoanRestructuringModificationDomain_639216265578517828" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ExtendedMaturityMember" xlink:label="us-gaap_ExtendedMaturityMember_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LoanRestructuringModificationDomain_639216265578517828" xlink:to="us-gaap_ExtendedMaturityMember_639216265578517828" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember" xlink:label="osbc_ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LoanRestructuringModificationDomain_639216265578517828" xlink:to="osbc_ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember_639216265578517828" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ExtendedMaturityAndInterestRateReductionMember" xlink:label="us-gaap_ExtendedMaturityAndInterestRateReductionMember_639216265578517828" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LoanRestructuringModificationDomain_639216265578517828" xlink:to="us-gaap_ExtendedMaturityAndInterestRateReductionMember_639216265578517828" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InterestRateReductionAndPaymentModificationMember" xlink:label="osbc_InterestRateReductionAndPaymentModificationMember_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LoanRestructuringModificationDomain_639216265578517828" xlink:to="osbc_InterestRateReductionAndPaymentModificationMember_639216265578523348" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ExtendedMaturityAndPaymentModificationMember" xlink:label="osbc_ExtendedMaturityAndPaymentModificationMember_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LoanRestructuringModificationDomain_639216265578517828" xlink:to="osbc_ExtendedMaturityAndPaymentModificationMember_639216265578523348" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueAxis_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_639216265578511712" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueAxis_639216265578523348" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueAxis_639216265578523348" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivables30To59DaysPastDueMember" xlink:label="us-gaap_FinancingReceivables30To59DaysPastDueMember_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" xlink:to="us-gaap_FinancingReceivables30To59DaysPastDueMember_639216265578523348" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivables60To89DaysPastDueMember" xlink:label="us-gaap_FinancingReceivables60To89DaysPastDueMember_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" xlink:to="us-gaap_FinancingReceivables60To89DaysPastDueMember_639216265578523348" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember" xlink:label="us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_639216265578523348" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" xlink:to="us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_639216265578523348" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialAssetPastDueMember" xlink:label="us-gaap_FinancialAssetPastDueMember_639216265578528584" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" xlink:to="us-gaap_FinancialAssetPastDueMember_639216265578528584" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialAssetNotPastDueMember" xlink:label="us-gaap_FinancialAssetNotPastDueMember_639216265578529906" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain_639216265578523348" xlink:to="us-gaap_FinancialAssetNotPastDueMember_639216265578529906" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableModificationsLineItems" xlink:label="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfFinancingReceivableTroubledDebtRestructuringsTable_639216265578511712" xlink:to="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod_639216265578529906" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod_639216265578529906" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableModifiedInPeriodToTotalFinancingReceivablesPercentage" xlink:label="osbc_FinancingReceivableModifiedInPeriodToTotalFinancingReceivablesPercentage_639216265578529906" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" xlink:to="osbc_FinancingReceivableModifiedInPeriodToTotalFinancingReceivablesPercentage_639216265578529906" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification" xlink:label="us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification_639216265578529906" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" xlink:to="us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification_639216265578529906" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification" xlink:label="us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification_639216265578529906" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" xlink:to="us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification_639216265578529906" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableModifiedWeightedAveragePaymentDelayFromModification" xlink:label="osbc_FinancingReceivableModifiedWeightedAveragePaymentDelayFromModification_639216265578535133" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" xlink:to="osbc_FinancingReceivableModifiedWeightedAveragePaymentDelayFromModification_639216265578535133" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FinancingReceivableModifiedInPeriodNumberOfContracts" xlink:label="osbc_FinancingReceivableModifiedInPeriodNumberOfContracts_639216265578535756" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancingReceivableModificationsLineItems_639216265578529906" xlink:to="osbc_FinancingReceivableModifiedInPeriodNumberOfContracts_639216265578535756" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureOtherRealEstateOwnedDetails" xlink:type="extended" xlink:title="99940501 - Disclosure - Other Real Estate Owned (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAbstract" xlink:label="us-gaap_RealEstateAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherRealEstateRollForward" xlink:label="us-gaap_OtherRealEstateRollForward_639216265578535756" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="us-gaap_OtherRealEstateRollForward_639216265578535756" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAcquiredThroughForeclosure" xlink:label="us-gaap_RealEstateAcquiredThroughForeclosure_639216265578535756" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherRealEstateRollForward_639216265578535756" xlink:to="us-gaap_RealEstateAcquiredThroughForeclosure_639216265578535756" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateAcquisitionsThroughForeclosuresNetOfAcquisitionAdjustmentsAndParticipation" xlink:label="osbc_RealEstateAcquisitionsThroughForeclosuresNetOfAcquisitionAdjustmentsAndParticipation_639216265578535756" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherRealEstateRollForward_639216265578535756" xlink:to="osbc_RealEstateAcquisitionsThroughForeclosuresNetOfAcquisitionAdjustmentsAndParticipation_639216265578535756" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateCostOfRealEstateSoldNetOfGainLoss" xlink:label="osbc_RealEstateCostOfRealEstateSoldNetOfGainLoss_639216265578540986" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherRealEstateRollForward_639216265578535756" xlink:to="osbc_RealEstateCostOfRealEstateSoldNetOfGainLoss_639216265578540986" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnedValuationAllowanceProvisionNetOfAdjustment" xlink:label="osbc_RealEstateOwnedValuationAllowanceProvisionNetOfAdjustment_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherRealEstateRollForward_639216265578535756" xlink:to="osbc_RealEstateOwnedValuationAllowanceProvisionNetOfAdjustment_639216265578541592" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="9" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAcquiredThroughForeclosure" xlink:label="us-gaap_RealEstateAcquiredThroughForeclosure_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherRealEstateRollForward_639216265578535756" xlink:to="us-gaap_RealEstateAcquiredThroughForeclosure_639216265578541592" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateOwnedValuationAllowanceRollForward" xlink:label="us-gaap_RealEstateOwnedValuationAllowanceRollForward_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="us-gaap_RealEstateOwnedValuationAllowanceRollForward_639216265578541592" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateOwnedValuationAllowance" xlink:label="us-gaap_RealEstateOwnedValuationAllowance_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateOwnedValuationAllowanceRollForward_639216265578541592" xlink:to="us-gaap_RealEstateOwnedValuationAllowance_639216265578541592" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnedValuationAllowanceProvisionBenefit" xlink:label="osbc_RealEstateOwnedValuationAllowanceProvisionBenefit_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateOwnedValuationAllowanceRollForward_639216265578541592" xlink:to="osbc_RealEstateOwnedValuationAllowanceProvisionBenefit_639216265578541592" order="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/netLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnedValuationAllowanceAmountsAppliedNetOfAdjustments" xlink:label="osbc_RealEstateOwnedValuationAllowanceAmountsAppliedNetOfAdjustments_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateOwnedValuationAllowanceRollForward_639216265578541592" xlink:to="osbc_RealEstateOwnedValuationAllowanceAmountsAppliedNetOfAdjustments_639216265578541592" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateOwnedValuationAllowance" xlink:label="us-gaap_RealEstateOwnedValuationAllowance_6392162655785415921" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateOwnedValuationAllowanceRollForward_639216265578541592" xlink:to="us-gaap_RealEstateOwnedValuationAllowance_6392162655785415921" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract" xlink:label="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RealEstateAbstract" xlink:to="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_GainsLossesOnSalesOfOtherRealEstateBeforeProvisionForValuationAllowance" xlink:label="osbc_GainsLossesOnSalesOfOtherRealEstateBeforeProvisionForValuationAllowance_639216265578546818" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" xlink:to="osbc_GainsLossesOnSalesOfOtherRealEstateBeforeProvisionForValuationAllowance_639216265578546818" order="1" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateOwnedValuationAllowanceProvisionBenefit" xlink:label="osbc_RealEstateOwnedValuationAllowanceProvisionBenefit_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" xlink:to="osbc_RealEstateOwnedValuationAllowanceProvisionBenefit_639216265578547430" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateAcquiredThroughForeclosureOperatingIncomeExpenses" xlink:label="osbc_RealEstateAcquiredThroughForeclosureOperatingIncomeExpenses_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" xlink:to="osbc_RealEstateAcquiredThroughForeclosureOperatingIncomeExpenses_639216265578547430" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_LeaseRevenueForOtherRealEstate" xlink:label="osbc_LeaseRevenueForOtherRealEstate_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" xlink:to="osbc_LeaseRevenueForOtherRealEstate_639216265578547430" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ForeclosedRealEstateExpenseNetOfLeaseRevenue" xlink:label="osbc_ForeclosedRealEstateExpenseNetOfLeaseRevenue_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" xlink:to="osbc_ForeclosedRealEstateExpenseNetOfLeaseRevenue_639216265578547430" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateAcquiredThroughForeclosureGainLossOnTransferToRealEstateOwned" xlink:label="osbc_RealEstateAcquiredThroughForeclosureGainLossOnTransferToRealEstateOwned_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_OtherRealEstateOwnedExpensesRelatedToForeclosedAssetsAbstract_639216265578541592" xlink:to="osbc_RealEstateAcquiredThroughForeclosureGainLossOnTransferToRealEstateOwned_639216265578547430" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDepositsClassificationsOfDepositsDetails" xlink:type="extended" xlink:title="99940601 - Disclosure - Deposits - Classifications of Deposits (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsByTypeAbstract" xlink:label="us-gaap_DepositsByTypeAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestBearingDepositLiabilities" xlink:label="us-gaap_NoninterestBearingDepositLiabilities_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_NoninterestBearingDepositLiabilities_639216265578547430" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsSavingsDeposits" xlink:label="us-gaap_DepositsSavingsDeposits_639216265578547430" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_DepositsSavingsDeposits_639216265578547430" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsNegotiableOrderOfWithdrawalNOW" xlink:label="us-gaap_DepositsNegotiableOrderOfWithdrawalNOW_639216265578553279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_DepositsNegotiableOrderOfWithdrawalNOW_639216265578553279" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepositsMoneyMarketDeposits" xlink:label="us-gaap_DepositsMoneyMarketDeposits_639216265578553279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_DepositsMoneyMarketDeposits_639216265578553279" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TimeDepositsLessThan100000" xlink:label="us-gaap_TimeDepositsLessThan100000_639216265578553279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_TimeDepositsLessThan100000_639216265578553279" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TimeDeposits100000To250000" xlink:label="osbc_TimeDeposits100000To250000_639216265578553279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="osbc_TimeDeposits100000To250000_639216265578553279" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TimeDeposits250000OrMore" xlink:label="osbc_TimeDeposits250000OrMore_639216265578553279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="osbc_TimeDeposits250000OrMore_639216265578553279" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Deposits" xlink:label="us-gaap_Deposits_639216265578553279" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DepositsByTypeAbstract" xlink:to="us-gaap_Deposits_639216265578553279" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBorrowingsSummaryDetails" xlink:type="extended" xlink:title="99940701 - Disclosure - Borrowings - Summary (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable_639216265578558512" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtInstrumentTable_639216265578558512" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578558512" xlink:to="us-gaap_DebtInstrumentAxis_639216265578559118" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis_639216265578559118" xlink:to="us-gaap_DebtInstrumentNameDomain_639216265578559118" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578559118" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember_639216265578559118" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherShortTermBorrowingsMember" xlink:label="osbc_OtherShortTermBorrowingsMember_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578559118" xlink:to="osbc_OtherShortTermBorrowingsMember_639216265578559118" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_JuniorSubordinatedDebtMember" xlink:label="us-gaap_JuniorSubordinatedDebtMember_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578559118" xlink:to="us-gaap_JuniorSubordinatedDebtMember_639216265578559118" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubordinatedDebtMember" xlink:label="us-gaap_SubordinatedDebtMember_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578559118" xlink:to="us-gaap_SubordinatedDebtMember_639216265578559118" order="4" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NotesPayableToBanksMember" xlink:label="us-gaap_NotesPayableToBanksMember_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578559118" xlink:to="us-gaap_NotesPayableToBanksMember_639216265578559118" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems_639216265578559118" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578558512" xlink:to="us-gaap_DebtInstrumentLineItems_639216265578559118" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmount_639216265578564346" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578559118" xlink:to="us-gaap_DebtLongtermAndShorttermCombinedAmount_639216265578564346" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureBorrowingsAdditionalInformationDetails" xlink:type="extended" xlink:title="99940702 - Disclosure - Borrowings - Additional information (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract_635641914088975110" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable_639216265578564968" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtDisclosureAbstract_635641914088975110" xlink:to="us-gaap_DebtInstrumentTable_639216265578564968" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis_639216265578564968" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578564968" xlink:to="us-gaap_DebtInstrumentAxis_639216265578564968" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain_639216265578564968" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis_639216265578564968" xlink:to="us-gaap_DebtInstrumentNameDomain_639216265578564968" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember_639216265578564968" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578564968" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember_639216265578564968" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankAdvancesMember" xlink:label="us-gaap_FederalHomeLoanBankAdvancesMember_639216265578564968" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578564968" xlink:to="us-gaap_FederalHomeLoanBankAdvancesMember_639216265578564968" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_SubordinatedNotesDue2031Member" xlink:label="osbc_SubordinatedNotesDue2031Member_639216265578570199" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain_639216265578564968" xlink:to="osbc_SubordinatedNotesDue2031Member_639216265578570199" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578564968" xlink:to="srt_RangeAxis_639216265578570836" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="srt_RangeMember_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_639216265578570836" xlink:to="srt_RangeMember_639216265578570836" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578570836" xlink:to="srt_MaximumMember_639216265578570836" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PledgedStatusAxis" xlink:label="us-gaap_PledgedStatusAxis_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578564968" xlink:to="us-gaap_PledgedStatusAxis_639216265578570836" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PledgedStatusDomain" xlink:label="us-gaap_PledgedStatusDomain_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PledgedStatusAxis_639216265578570836" xlink:to="us-gaap_PledgedStatusDomain_639216265578570836" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetPledgedAsCollateralWithRightMember" xlink:label="us-gaap_AssetPledgedAsCollateralWithRightMember_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PledgedStatusDomain_639216265578570836" xlink:to="us-gaap_AssetPledgedAsCollateralWithRightMember_639216265578570836" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PledgingPurposeAxis" xlink:label="us-gaap_PledgingPurposeAxis_639216265578570836" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578564968" xlink:to="us-gaap_PledgingPurposeAxis_639216265578570836" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PledgingPurposeDomain" xlink:label="us-gaap_PledgingPurposeDomain_639216265578576069" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PledgingPurposeAxis_639216265578570836" xlink:to="us-gaap_PledgingPurposeDomain_639216265578576069" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PledgingPurposeDomain_639216265578576069" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseMember_639216265578576759" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578564968" xlink:to="us-gaap_DebtInstrumentLineItems_639216265578576759" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecurities" xlink:label="us-gaap_DebtSecurities_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_DebtSecurities_639216265578576759" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAverageAmountOutstanding" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAverageAmountOutstanding_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAverageAmountOutstanding_639216265578576759" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SecuritiesSoldUnderAgreementsToRepurchaseAverageRatePaid" xlink:label="srt_SecuritiesSoldUnderAgreementsToRepurchaseAverageRatePaid_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="srt_SecuritiesSoldUnderAgreementsToRepurchaseAverageRatePaid_639216265578576759" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase" xlink:label="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_639216265578576759" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NumberOfCustomersHavingSecuredBalancesExceedingSpecifiedPercentageOfStockholdersEquity" xlink:label="osbc_NumberOfCustomersHavingSecuredBalancesExceedingSpecifiedPercentageOfStockholdersEquity_639216265578576759" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="osbc_NumberOfCustomersHavingSecuredBalancesExceedingSpecifiedPercentageOfStockholdersEquity_639216265578576759" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ThresholdForDisclosurePercentageOfStockholdersEquity" xlink:label="osbc_ThresholdForDisclosurePercentageOfStockholdersEquity_639216265578582555" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="osbc_ThresholdForDisclosurePercentageOfStockholdersEquity_639216265578582555" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FederalHomeLoanBankAdvancesAsPercentageOfTotalAssets" xlink:label="osbc_FederalHomeLoanBankAdvancesAsPercentageOfTotalAssets_639216265578583329" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="osbc_FederalHomeLoanBankAdvancesAsPercentageOfTotalAssets_639216265578583329" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch" xlink:label="us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch_639216265578583329" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch_639216265578583329" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_639216265578583329" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_639216265578583329" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankStock" xlink:label="us-gaap_FederalHomeLoanBankStock_639216265578583329" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_FederalHomeLoanBankStock_639216265578583329" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FederalHomeLoanBankAdvancesGeneralDebtObligations" xlink:label="osbc_FederalHomeLoanBankAdvancesGeneralDebtObligations_639216265578583329" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="osbc_FederalHomeLoanBankAdvancesGeneralDebtObligations_639216265578583329" order="11" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1" xlink:label="us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1_639216265578583329" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1_639216265578583329" order="12" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:label="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_639216265578588534" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_639216265578588534" order="13" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount_639216265578589577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_DebtInstrumentFaceAmount_639216265578589577" order="14" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_639216265578589577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_639216265578589577" order="15" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="6" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration" xlink:label="us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration_639216265578589577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration_639216265578589577" order="16" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_639216265578589577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_639216265578589577" order="17" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RepaymentsOfSubordinatedDebt" xlink:label="us-gaap_RepaymentsOfSubordinatedDebt_639216265578589577" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_RepaymentsOfSubordinatedDebt_639216265578589577" order="18" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount_639216265578594782" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_DebtInstrumentCarryingAmount_639216265578594782" order="19" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_639216265578595296" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578576759" xlink:to="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_639216265578595296" order="20" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureJuniorSubordinatedDebenturesIssuanceDetails" xlink:type="extended" xlink:title="99940801 - Disclosure - Junior Subordinated Debentures - Issuance (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubordinatedBorrowingsAbstract" xlink:label="us-gaap_SubordinatedBorrowingsAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable_639216265578595296" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubordinatedBorrowingsAbstract" xlink:to="us-gaap_DebtInstrumentTable_639216265578595296" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis_639216265578595296" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578595296" xlink:to="us-gaap_LongtermDebtTypeAxis_639216265578595296" order="1" use="optional" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain_639216265578600506" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeAxis_639216265578595296" xlink:to="us-gaap_LongtermDebtTypeDomain_639216265578600506" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_JuniorSubordinatedDebtMember" xlink:label="us-gaap_JuniorSubordinatedDebtMember_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain_639216265578600506" xlink:to="us-gaap_JuniorSubordinatedDebtMember_639216265578601016" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesAxis" xlink:label="srt_ConsolidatedEntitiesAxis_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578595296" xlink:to="srt_ConsolidatedEntitiesAxis_639216265578601016" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="srt_ConsolidatedEntitiesDomain_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidatedEntitiesAxis_639216265578601016" xlink:to="srt_ConsolidatedEntitiesDomain_639216265578601016" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OldSecondCapitalTrustIIMember" xlink:label="osbc_OldSecondCapitalTrustIIMember_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidatedEntitiesDomain_639216265578601016" xlink:to="osbc_OldSecondCapitalTrustIIMember_639216265578601016" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578595296" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodAxis_639216265578601016" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodAxis_639216265578601016" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodDomain_639216265578601016" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodOneMember_639216265578601016" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain_639216265578601016" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodOneMember_639216265578601016" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems_639216265578606222" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable_639216265578595296" xlink:to="us-gaap_DebtInstrumentLineItems_639216265578606222" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfTrustPreferredSecurities" xlink:label="us-gaap_ProceedsFromIssuanceOfTrustPreferredSecurities_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="us-gaap_ProceedsFromIssuanceOfTrustPreferredSecurities_639216265578606742" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TrustPreferredSecuritiesMaturityPeriod" xlink:label="osbc_TrustPreferredSecuritiesMaturityPeriod_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="osbc_TrustPreferredSecuritiesMaturityPeriod_639216265578606742" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TrustPreferredSecuritiesCashDistributionFixedRatePercentage" xlink:label="osbc_TrustPreferredSecuritiesCashDistributionFixedRatePercentage_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="osbc_TrustPreferredSecuritiesCashDistributionFixedRatePercentage_639216265578606742" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TrustPreferredSecuritiesBasisSpreadOnVariableRate" xlink:label="osbc_TrustPreferredSecuritiesBasisSpreadOnVariableRate_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="osbc_TrustPreferredSecuritiesBasisSpreadOnVariableRate_639216265578606742" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TrustPreferredSecuritiesDescriptionOfVariableRateBasis" xlink:label="osbc_TrustPreferredSecuritiesDescriptionOfVariableRateBasis_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="osbc_TrustPreferredSecuritiesDescriptionOfVariableRateBasis_639216265578606742" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_639216265578606742" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="7" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust" xlink:label="us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_639216265578606742" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_639216265578606742" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="9" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet_639216265578611943" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="us-gaap_DeferredFinanceCostsNet_639216265578611943" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TrustPreferredSecuritiesIssuanceCostAmortizationPeriod" xlink:label="osbc_TrustPreferredSecuritiesIssuanceCostAmortizationPeriod_639216265578612451" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems_639216265578606222" xlink:to="osbc_TrustPreferredSecuritiesIssuanceCostAmortizationPeriod_639216265578612451" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEquityCompensationPlansDetails" xlink:type="extended" xlink:title="99940901 - Disclosure - Equity Compensation Plans (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636229294143239614" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578612451" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_636229294143239614" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578612451" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis_639216265578612451" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578612451" xlink:to="us-gaap_AwardTypeAxis_639216265578612451" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578612451" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis_639216265578612451" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578612451" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RestrictedStockAndRestrictedStockUnitsMember" xlink:label="osbc_RestrictedStockAndRestrictedStockUnitsMember_639216265578612451" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578612451" xlink:to="osbc_RestrictedStockAndRestrictedStockUnitsMember_639216265578612451" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578612451" xlink:to="us-gaap_PlanNameAxis_639216265578618158" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis_639216265578618158" xlink:to="us-gaap_PlanNameDomain_639216265578618158" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_EquityIncentivePlan2019Member" xlink:label="osbc_EquityIncentivePlan2019Member_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain_639216265578618158" xlink:to="osbc_EquityIncentivePlan2019Member_639216265578618158" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578612451" xlink:to="srt_RangeAxis_639216265578618158" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="srt_RangeMember_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_639216265578618158" xlink:to="srt_RangeMember_639216265578618158" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578618158" xlink:to="srt_MinimumMember_639216265578618158" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578618158" xlink:to="srt_MaximumMember_639216265578618158" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578612451" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_639216265578623357" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_639216265578623357" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_639216265578623867" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_639216265578623867" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_639216265578623867" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_639216265578623867" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ConditionPerformanceMeasureProRataVestingShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentage" xlink:label="osbc_ConditionPerformanceMeasureProRataVestingShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentage_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="osbc_ConditionPerformanceMeasureProRataVestingShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentage_639216265578623867" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ConditionPerformanceMeasureFullyEarnedVestingShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentage" xlink:label="osbc_ConditionPerformanceMeasureFullyEarnedVestingShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentage_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="osbc_ConditionPerformanceMeasureFullyEarnedVestingShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentage_639216265578623867" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ShareBasedPaymentArrangementTaxBenefitRealizedFromCompensationCost" xlink:label="osbc_ShareBasedPaymentArrangementTaxBenefitRealizedFromCompensationCost_639216265578623867" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578618158" xlink:to="osbc_ShareBasedPaymentArrangementTaxBenefitRealizedFromCompensationCost_639216265578623867" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEquityCompensationPlansRestrictedStockAndRsusDetails" xlink:type="extended" xlink:title="99940902 - Disclosure - Equity Compensation Plans - Restricted Stock and RSUs (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_635641893811854341" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578629584" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_635641893811854341" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578629584" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis_639216265578629584" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578629584" xlink:to="us-gaap_AwardTypeAxis_639216265578629584" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578629584" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis_639216265578629584" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578629584" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RestrictedStockAndRestrictedStockUnitsMember" xlink:label="osbc_RestrictedStockAndRestrictedStockUnitsMember_639216265578629584" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578629584" xlink:to="osbc_RestrictedStockAndRestrictedStockUnitsMember_639216265578629584" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578629584" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_639216265578629584" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578629584" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578629584" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_639216265578635300" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_639216265578635300" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_639216265578635300" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_639216265578635300" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_639216265578635300" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_639216265578635300" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_639216265578635300" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_639216265578635300" order="4" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_6392162655786353001" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_6392162655786353001" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578629584" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_639216265578640500" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_639216265578640500" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_639216265578641063" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_639216265578641063" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_639216265578641063" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_639216265578641063" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_639216265578641063" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_639216265578641063" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_639216265578641063" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_639216265578635300" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_639216265578641063" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_639216265578641063" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_639216265578629584" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_639216265578641063" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_639216265578641063" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_639216265578641063" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_639216265578641063" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_639216265578646301" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_639216265578641063" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_639216265578646301" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureEarningsPerShareReconciliationDetails" xlink:type="extended" xlink:title="99941001 - Disclosure - Earnings Per Share - Reconciliation (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ScheduleOfEarningsPerShareBasicAndDilutedTable" xlink:label="osbc_ScheduleOfEarningsPerShareBasicAndDilutedTable_639216265578646855" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="osbc_ScheduleOfEarningsPerShareBasicAndDilutedTable_639216265578646855" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis_639216265578646855" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_ScheduleOfEarningsPerShareBasicAndDilutedTable_639216265578646855" xlink:to="us-gaap_AwardTypeAxis_639216265578646855" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578646855" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis_639216265578646855" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578646855" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RestrictedStockAndRestrictedStockUnitsMember" xlink:label="osbc_RestrictedStockAndRestrictedStockUnitsMember_639216265578646855" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_639216265578646855" xlink:to="osbc_RestrictedStockAndRestrictedStockUnitsMember_639216265578646855" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_EarningsPerShareBasicAndDilutedLineItems" xlink:label="osbc_EarningsPerShareBasicAndDilutedLineItems_639216265578670490" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_ScheduleOfEarningsPerShareBasicAndDilutedTable_639216265578646855" xlink:to="osbc_EarningsPerShareBasicAndDilutedLineItems_639216265578670490" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasicAbstract" xlink:label="us-gaap_EarningsPerShareBasicAbstract_639216265578670490" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_EarningsPerShareBasicAndDilutedLineItems_639216265578670490" xlink:to="us-gaap_EarningsPerShareBasicAbstract_639216265578670490" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_639216265578670490" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareBasicAbstract_639216265578670490" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_639216265578670490" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_639216265578670490" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareBasicAbstract_639216265578670490" xlink:to="us-gaap_NetIncomeLoss_639216265578670490" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic_639216265578670490" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareBasicAbstract_639216265578670490" xlink:to="us-gaap_EarningsPerShareBasic_639216265578670490" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDilutedAbstract" xlink:label="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_EarningsPerShareBasicAndDilutedLineItems_639216265578670490" xlink:to="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_6392162655786704901" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_6392162655786704901" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_639216265578675756" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" xlink:to="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_639216265578675756" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_639216265578676290" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_639216265578676290" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_639216265578676290" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" xlink:to="us-gaap_NetIncomeLoss_639216265578676290" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted_639216265578676290" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareDilutedAbstract_639216265578670490" xlink:to="us-gaap_EarningsPerShareDiluted_639216265578676290" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersDetails" xlink:type="extended" xlink:title="99941101 - Disclosure - Regulatory &amp; Capital Matters (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BankingAndThriftInterestAbstract" xlink:label="us-gaap_BankingAndThriftInterestAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable" xlink:label="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578676290" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BankingAndThriftInterestAbstract" xlink:to="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578676290" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578676290" xlink:to="srt_RangeAxis_639216265578682064" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="srt_RangeMember_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_639216265578682064" xlink:to="srt_RangeMember_639216265578682064" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578682064" xlink:to="srt_MinimumMember_639216265578682064" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesAxis" xlink:label="srt_ConsolidatedEntitiesAxis_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578676290" xlink:to="srt_ConsolidatedEntitiesAxis_639216265578682064" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="srt_ConsolidatedEntitiesDomain_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidatedEntitiesAxis_639216265578682064" xlink:to="srt_ConsolidatedEntitiesDomain_639216265578682064" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SubsidiariesMember" xlink:label="srt_SubsidiariesMember_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidatedEntitiesDomain_639216265578682064" xlink:to="srt_SubsidiariesMember_639216265578682064" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems" xlink:label="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578676290" xlink:to="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalToAverageAssets" xlink:label="us-gaap_TierOneLeverageCapitalToAverageAssets_639216265578682064" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="us-gaap_TierOneLeverageCapitalToAverageAssets_639216265578682064" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="5" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_IncreaseInTierOneLeverageCapital" xlink:label="osbc_IncreaseInTierOneLeverageCapital_639216265578687302" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="osbc_IncreaseInTierOneLeverageCapital_639216265578687302" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalToRiskWeightedAssets" xlink:label="us-gaap_CapitalToRiskWeightedAssets_639216265578687838" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="us-gaap_CapitalToRiskWeightedAssets_639216265578687838" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="8" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_IncreaseInCapitalToRiskWeightedAssetsRatio" xlink:label="osbc_IncreaseInCapitalToRiskWeightedAssetsRatio_639216265578687838" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="osbc_IncreaseInCapitalToRiskWeightedAssetsRatio_639216265578687838" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BoardDesignatedTierOneLeverageCapitalToAverageAssets" xlink:label="osbc_BoardDesignatedTierOneLeverageCapitalToAverageAssets_639216265578687838" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="osbc_BoardDesignatedTierOneLeverageCapitalToAverageAssets_639216265578687838" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfDividends" xlink:label="us-gaap_PaymentsOfDividends_639216265578687838" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="us-gaap_PaymentsOfDividends_639216265578687838" order="6" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_BoardDesignatedCapitalToRiskWeightedAssets" xlink:label="osbc_BoardDesignatedCapitalToRiskWeightedAssets_639216265578687838" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578682064" xlink:to="osbc_BoardDesignatedCapitalToRiskWeightedAssets_639216265578687838" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersCapitalLevelsAndIndustryDefinedRegulatoryMinimumsDetails" xlink:type="extended" xlink:title="99941102 - Disclosure - Regulatory &amp; Capital Matters - Capital Levels and Industry Defined Regulatory Minimums (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BankingAndThriftInterestAbstract" xlink:label="us-gaap_BankingAndThriftInterestAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable" xlink:label="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BankingAndThriftInterestAbstract" xlink:to="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578693737" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesAxis" xlink:label="srt_ConsolidatedEntitiesAxis_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578693737" xlink:to="srt_ConsolidatedEntitiesAxis_639216265578693737" order="1" use="optional" priority="3" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain" xlink:label="srt_ConsolidatedEntitiesDomain_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidatedEntitiesAxis_639216265578693737" xlink:to="srt_ConsolidatedEntitiesDomain_639216265578693737" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SubsidiariesMember" xlink:label="srt_SubsidiariesMember_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidatedEntitiesDomain_639216265578693737" xlink:to="srt_SubsidiariesMember_639216265578693737" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems" xlink:label="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_639216265578693737" xlink:to="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CapitalCommonAbstract" xlink:label="osbc_CapitalCommonAbstract_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="osbc_CapitalCommonAbstract_639216265578693737" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCapitalCommonEquity" xlink:label="osbc_TierOneRiskBasedCapitalCommonEquity_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CapitalCommonAbstract_639216265578693737" xlink:to="osbc_TierOneRiskBasedCapitalCommonEquity_639216265578693737" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCommonCapitalRequiredForCapitalAdequacy" xlink:label="osbc_TierOneRiskBasedCommonCapitalRequiredForCapitalAdequacy_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CapitalCommonAbstract_639216265578693737" xlink:to="osbc_TierOneRiskBasedCommonCapitalRequiredForCapitalAdequacy_639216265578693737" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCommonCapitalRequiredToBeWellCapitalized" xlink:label="osbc_TierOneRiskBasedCommonCapitalRequiredToBeWellCapitalized_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CapitalCommonAbstract_639216265578693737" xlink:to="osbc_TierOneRiskBasedCommonCapitalRequiredToBeWellCapitalized_639216265578693737" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommonCapitalToRiskBasedRatiosAbstract" xlink:label="osbc_CommonCapitalToRiskBasedRatiosAbstract_639216265578693737" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="osbc_CommonCapitalToRiskBasedRatiosAbstract_639216265578693737" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCapitalCommonEquityToRiskWeightedAssets" xlink:label="osbc_TierOneRiskBasedCapitalCommonEquityToRiskWeightedAssets_639216265578699230" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CommonCapitalToRiskBasedRatiosAbstract_639216265578693737" xlink:to="osbc_TierOneRiskBasedCapitalCommonEquityToRiskWeightedAssets_639216265578699230" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCommonCapitalRequiredForCapitalAdequacyToRiskWeightedAssets" xlink:label="osbc_TierOneRiskBasedCommonCapitalRequiredForCapitalAdequacyToRiskWeightedAssets_639216265578699915" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CommonCapitalToRiskBasedRatiosAbstract_639216265578693737" xlink:to="osbc_TierOneRiskBasedCommonCapitalRequiredForCapitalAdequacyToRiskWeightedAssets_639216265578699915" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCommonCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets" xlink:label="osbc_TierOneRiskBasedCommonCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CommonCapitalToRiskBasedRatiosAbstract_639216265578693737" xlink:to="osbc_TierOneRiskBasedCommonCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_639216265578700305" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalAbstract" xlink:label="us-gaap_CapitalAbstract_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="us-gaap_CapitalAbstract_639216265578700305" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Capital" xlink:label="us-gaap_Capital_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalAbstract_639216265578700305" xlink:to="us-gaap_Capital_639216265578700305" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalRequiredForCapitalAdequacy" xlink:label="us-gaap_CapitalRequiredForCapitalAdequacy_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalAbstract_639216265578700305" xlink:to="us-gaap_CapitalRequiredForCapitalAdequacy_639216265578700305" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalRequiredToBeWellCapitalized" xlink:label="us-gaap_CapitalRequiredToBeWellCapitalized_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalAbstract_639216265578700305" xlink:to="us-gaap_CapitalRequiredToBeWellCapitalized_639216265578700305" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CapitalToRiskBasedRatiosAbstract" xlink:label="osbc_CapitalToRiskBasedRatiosAbstract_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="osbc_CapitalToRiskBasedRatiosAbstract_639216265578700305" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalToRiskWeightedAssets" xlink:label="us-gaap_CapitalToRiskWeightedAssets_639216265578700305" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CapitalToRiskBasedRatiosAbstract_639216265578700305" xlink:to="us-gaap_CapitalToRiskWeightedAssets_639216265578700305" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets" xlink:label="us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets_639216265578705783" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CapitalToRiskBasedRatiosAbstract_639216265578700305" xlink:to="us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets_639216265578705783" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets" xlink:label="us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_639216265578706192" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_CapitalToRiskBasedRatiosAbstract_639216265578700305" xlink:to="us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_639216265578706192" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneRiskBasedCapitalAbstract" xlink:label="us-gaap_TierOneRiskBasedCapitalAbstract_639216265578706192" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="us-gaap_TierOneRiskBasedCapitalAbstract_639216265578706192" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneRiskBasedCapital" xlink:label="us-gaap_TierOneRiskBasedCapital_639216265578706192" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TierOneRiskBasedCapitalAbstract_639216265578706192" xlink:to="us-gaap_TierOneRiskBasedCapital_639216265578706192" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer" xlink:label="osbc_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer_639216265578706192" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TierOneRiskBasedCapitalAbstract_639216265578706192" xlink:to="osbc_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer_639216265578706192" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized" xlink:label="us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized_639216265578706192" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TierOneRiskBasedCapitalAbstract_639216265578706192" xlink:to="us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized_639216265578706192" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RiskBasedRatiosAbstract" xlink:label="us-gaap_RiskBasedRatiosAbstract_639216265578706192" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="us-gaap_RiskBasedRatiosAbstract_639216265578706192" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets" xlink:label="us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets_639216265578711693" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RiskBasedRatiosAbstract_639216265578706192" xlink:to="us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets_639216265578711693" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBufferToRiskWeightedAssets" xlink:label="osbc_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBufferToRiskWeightedAssets_639216265578712095" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RiskBasedRatiosAbstract_639216265578706192" xlink:to="osbc_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBufferToRiskWeightedAssets_639216265578712095" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets" xlink:label="us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_639216265578712095" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RiskBasedRatiosAbstract_639216265578706192" xlink:to="us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets_639216265578712095" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalAbstract" xlink:label="us-gaap_TierOneLeverageCapitalAbstract_639216265578712095" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="us-gaap_TierOneLeverageCapitalAbstract_639216265578712095" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapital" xlink:label="us-gaap_TierOneLeverageCapital_639216265578712095" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TierOneLeverageCapitalAbstract_639216265578712095" xlink:to="us-gaap_TierOneLeverageCapital_639216265578712095" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy" xlink:label="us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy_639216265578712095" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TierOneLeverageCapitalAbstract_639216265578712095" xlink:to="us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy_639216265578712095" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized" xlink:label="us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized_639216265578717333" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TierOneLeverageCapitalAbstract_639216265578712095" xlink:to="us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized_639216265578717333" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LeverageRatiosAbstract" xlink:label="us-gaap_LeverageRatiosAbstract_639216265578717992" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_639216265578693737" xlink:to="us-gaap_LeverageRatiosAbstract_639216265578717992" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalToAverageAssets" xlink:label="us-gaap_TierOneLeverageCapitalToAverageAssets_639216265578717992" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeverageRatiosAbstract_639216265578717992" xlink:to="us-gaap_TierOneLeverageCapitalToAverageAssets_639216265578717992" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets" xlink:label="us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets_639216265578717992" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeverageRatiosAbstract_639216265578717992" xlink:to="us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets_639216265578717992" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets" xlink:label="us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets_639216265578717992" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeverageRatiosAbstract_639216265578717992" xlink:to="us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets_639216265578717992" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureRegulatoryCapitalMattersDividendRestrictionsDetails" xlink:type="extended" xlink:title="99941103 - Disclosure - Regulatory &amp; Capital Matters - Dividend Restrictions (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BankingAndThriftInterestAbstract" xlink:label="us-gaap_BankingAndThriftInterestAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DividendRestrictionsAndDeferralsAbstract" xlink:label="osbc_DividendRestrictionsAndDeferralsAbstract_639216265578724562" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BankingAndThriftInterestAbstract" xlink:to="osbc_DividendRestrictionsAndDeferralsAbstract_639216265578724562" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DividendRestrictionsNumberOfPreviousYearsRetainedProfit" xlink:label="osbc_DividendRestrictionsNumberOfPreviousYearsRetainedProfit_639216265578724562" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DividendRestrictionsAndDeferralsAbstract_639216265578724562" xlink:to="osbc_DividendRestrictionsNumberOfPreviousYearsRetainedProfit_639216265578724562" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmountAvailableForDividendDistributionWithoutAffectingCapitalAdequacyRequirements" xlink:label="us-gaap_AmountAvailableForDividendDistributionWithoutAffectingCapitalAdequacyRequirements_639216265578724562" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DividendRestrictionsAndDeferralsAbstract_639216265578724562" xlink:to="us-gaap_AmountAvailableForDividendDistributionWithoutAffectingCapitalAdequacyRequirements_639216265578724562" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TierOneCommonEquityCapitalDistributionLimitationMinimumRegulatoryCapitalPercentageNextTwelveMonths" xlink:label="osbc_TierOneCommonEquityCapitalDistributionLimitationMinimumRegulatoryCapitalPercentageNextTwelveMonths_639216265578724562" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_DividendRestrictionsAndDeferralsAbstract_639216265578724562" xlink:to="osbc_TierOneCommonEquityCapitalDistributionLimitationMinimumRegulatoryCapitalPercentageNextTwelveMonths_639216265578724562" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsDetails" xlink:type="extended" xlink:title="99941201 - Disclosure - Fair Value Measurements (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3_639216265578724562" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3_639216265578724562" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsRecurringDetails" xlink:type="extended" xlink:title="99941202 - Disclosure - Fair Value Measurements - Recurring (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578730454" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578730454" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain_639216265578730454" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain_639216265578730454" xlink:to="us-gaap_FairValueMeasurementsRecurringMember_639216265578730454" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578730454" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578730454" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578730454" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578730454" xlink:to="us-gaap_FairValueInputsLevel1Member_639216265578730454" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member_639216265578730454" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578730454" xlink:to="us-gaap_FairValueInputsLevel2Member_639216265578730454" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member_639216265578736456" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578730454" xlink:to="us-gaap_FairValueInputsLevel3Member_639216265578736456" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578737421" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578737421" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="us-gaap_USTreasurySecuritiesMember_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_USTreasurySecuritiesMember_639216265578737421" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember" xlink:label="us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_639216265578737421" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember" xlink:label="osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember_639216265578737421" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578737421" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedMortgageObligationsMember" xlink:label="us-gaap_CollateralizedMortgageObligationsMember_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_CollateralizedMortgageObligationsMember_639216265578737421" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_639216265578737421" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_AssetBackedSecuritiesMember_639216265578737421" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralizedLoanObligationsMember" xlink:label="us-gaap_CollateralizedLoanObligationsMember_639216265578743037" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_CollateralizedLoanObligationsMember_639216265578743037" order="7" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember" xlink:label="us-gaap_EquitySecuritiesMember_639216265578743037" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578737421" xlink:to="us-gaap_EquitySecuritiesMember_639216265578743037" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_639216265578743037" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_639216265578743037" order="4" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain_639216265578743037" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentRiskAxis_639216265578743037" xlink:to="us-gaap_DerivativeContractTypeDomain_639216265578743037" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateContractMember" xlink:label="us-gaap_InterestRateContractMember_639216265578743037" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578743037" xlink:to="us-gaap_InterestRateContractMember_639216265578743037" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForwardContractsMember" xlink:label="us-gaap_ForwardContractsMember_639216265578743037" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578743037" xlink:to="us-gaap_ForwardContractsMember_639216265578743037" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember" xlink:label="us-gaap_InterestRateSwapMember_639216265578748465" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578743037" xlink:to="us-gaap_InterestRateSwapMember_639216265578748465" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578748757" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578730454" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578748757" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578748757" xlink:to="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578748757" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578748757" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoansHeldForSaleFairValueDisclosure" xlink:label="us-gaap_LoansHeldForSaleFairValueDisclosure_639216265578748757" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" xlink:to="us-gaap_LoansHeldForSaleFairValueDisclosure_639216265578748757" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ServicingAssetAtFairValueAmount" xlink:label="us-gaap_ServicingAssetAtFairValueAmount_639216265578748757" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" xlink:to="us-gaap_ServicingAssetAtFairValueAmount_639216265578748757" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeAssets" xlink:label="us-gaap_DerivativeAssets_639216265578748757" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" xlink:to="us-gaap_DerivativeAssets_639216265578748757" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure_639216265578754425" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract_639216265578748757" xlink:to="us-gaap_AssetsFairValueDisclosure_639216265578754425" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract_639216265578754425" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578748757" xlink:to="us-gaap_LiabilitiesFairValueDisclosureAbstract_639216265578754425" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilities" xlink:label="us-gaap_DerivativeLiabilities_639216265578754425" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesFairValueDisclosureAbstract_639216265578754425" xlink:to="us-gaap_DerivativeLiabilities_639216265578754425" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_639216265578754425" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesFairValueDisclosureAbstract_639216265578754425" xlink:to="us-gaap_LiabilitiesFairValueDisclosure_639216265578754425" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsChangesInLevel3Details" xlink:type="extended" xlink:title="99941203 - Disclosure - Fair Value Measurements - Changes in Level 3 (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:label="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_639216265578760036" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_639216265578760036" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578760036" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578760036" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578760036" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578760036" xlink:to="us-gaap_AssetBackedSecuritiesMember_639216265578760036" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578760036" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578760036" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageServicingRightsMember" xlink:label="osbc_MortgageServicingRightsMember_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578760036" xlink:to="osbc_MortgageServicingRightsMember_639216265578760036" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:label="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable_639216265578760036" xlink:to="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_639216265578760036" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_639216265578760036" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_639216265578760036" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_639216265578760036" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract" xlink:label="osbc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_639216265578760036" xlink:to="osbc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract_639216265578760036" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_639216265578760036" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossAbstract_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss_639216265578760036" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsAbstract" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsAbstract_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsAbstract_639216265578760036" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsAbstract_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_639216265578760036" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues_639216265578760036" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsAbstract_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues_639216265578760036" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlementsAbstract_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements_639216265578770681" order="3" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_639216265578760036" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_639216265578770681" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsQuantitativeAndQualitativeInformationDetails" xlink:type="extended" xlink:title="99941204 - Disclosure - Fair Value Measurements - Quantitative and Qualitative Information (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578770681" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain_639216265578770681" xlink:to="us-gaap_FairValueMeasurementsRecurringMember_639216265578770681" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="us-gaap_MeasurementInputTypeAxis_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="us-gaap_MeasurementInputTypeAxis_639216265578770681" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="us-gaap_MeasurementInputTypeDomain_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MeasurementInputTypeAxis_639216265578770681" xlink:to="us-gaap_MeasurementInputTypeDomain_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputDiscountRateMember" xlink:label="us-gaap_MeasurementInputDiscountRateMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MeasurementInputTypeDomain_639216265578770681" xlink:to="us-gaap_MeasurementInputDiscountRateMember_639216265578770681" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MeasurementInputLiquidityPremiumMember" xlink:label="osbc_MeasurementInputLiquidityPremiumMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MeasurementInputTypeDomain_639216265578770681" xlink:to="osbc_MeasurementInputLiquidityPremiumMember_639216265578770681" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputConstantPrepaymentRateMember" xlink:label="us-gaap_MeasurementInputConstantPrepaymentRateMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MeasurementInputTypeDomain_639216265578770681" xlink:to="us-gaap_MeasurementInputConstantPrepaymentRateMember_639216265578770681" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578770681" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578770681" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578770681" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetBackedSecuritiesMember" xlink:label="us-gaap_AssetBackedSecuritiesMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578770681" xlink:to="us-gaap_AssetBackedSecuritiesMember_639216265578770681" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_MortgageServicingRightsMember" xlink:label="osbc_MortgageServicingRightsMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578770681" xlink:to="osbc_MortgageServicingRightsMember_639216265578770681" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueAxis" xlink:label="us-gaap_ValuationTechniqueAxis_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="us-gaap_ValuationTechniqueAxis_639216265578770681" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="us-gaap_ValuationTechniqueDomain_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ValuationTechniqueAxis_639216265578770681" xlink:to="us-gaap_ValuationTechniqueDomain_639216265578770681" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DiscountedCashFlowValuationTechniqueMember" xlink:label="osbc_DiscountedCashFlowValuationTechniqueMember_639216265578770681" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ValuationTechniqueDomain_639216265578770681" xlink:to="osbc_DiscountedCashFlowValuationTechniqueMember_639216265578770681" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578785887" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578785887" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578785887" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" xlink:to="us-gaap_FairValueInputsLevel3Member_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="srt_RangeAxis_639216265578786317" order="6" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="srt_RangeMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis_639216265578786317" xlink:to="srt_RangeMember_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578786317" xlink:to="srt_MinimumMember_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578786317" xlink:to="srt_MaximumMember_639216265578786317" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_WeightedAverageMember" xlink:label="srt_WeightedAverageMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember_639216265578786317" xlink:to="srt_WeightedAverageMember_639216265578786317" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_639216265578770681" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_639216265578786317" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_639216265578786317" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ServicingAssetAtFairValueAmount" xlink:label="us-gaap_ServicingAssetAtFairValueAmount_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_639216265578786317" xlink:to="us-gaap_ServicingAssetAtFairValueAmount_639216265578786317" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/positiveLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_639216265578786317" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput_639216265578786317" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ServicingAssetMeasurementInput" xlink:label="us-gaap_ServicingAssetMeasurementInput_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_639216265578786317" xlink:to="us-gaap_ServicingAssetMeasurementInput_639216265578786317" order="4" use="optional" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValueMeasurementsNonrecurringDetails" xlink:type="extended" xlink:title="99941205 - Disclosure - Fair Value Measurements - Nonrecurring (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis_639216265578786317" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsNonrecurringMember" xlink:label="us-gaap_FairValueMeasurementsNonrecurringMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain_639216265578786317" xlink:to="us-gaap_FairValueMeasurementsNonrecurringMember_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578786317" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578786317" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" xlink:to="us-gaap_FairValueInputsLevel1Member_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" xlink:to="us-gaap_FairValueInputsLevel2Member_639216265578786317" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578786317" xlink:to="us-gaap_FairValueInputsLevel3Member_639216265578786317" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="us-gaap_FairValueByAssetClassAxis_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" xlink:to="us-gaap_FairValueByAssetClassAxis_639216265578786317" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByAssetClassAxis_639216265578786317" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ImpairedLoansMember" xlink:label="osbc_ImpairedLoansMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_639216265578786317" xlink:to="osbc_ImpairedLoansMember_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OtherRealEstateOwnedMember" xlink:label="osbc_OtherRealEstateOwnedMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_639216265578786317" xlink:to="osbc_OtherRealEstateOwnedMember_639216265578786317" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="us-gaap_FairValueByMeasurementBasisAxis_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" xlink:to="us-gaap_FairValueByMeasurementBasisAxis_639216265578786317" order="4" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementBasisAxis_639216265578786317" xlink:to="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578786317" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="us-gaap_CarryingReportedAmountFairValueDisclosureMember_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578786317" xlink:to="us-gaap_CarryingReportedAmountFairValueDisclosureMember_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_639216265578786317" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="us-gaap_AssetsFairValueDisclosure_639216265578786317" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ImpairedFinancingReceivableRelatedAllowanceIncludingPurchasedCreditImpairedLoansAdjustment" xlink:label="osbc_ImpairedFinancingReceivableRelatedAllowanceIncludingPurchasedCreditImpairedLoansAdjustment_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="osbc_ImpairedFinancingReceivableRelatedAllowanceIncludingPurchasedCreditImpairedLoansAdjustment_639216265578786317" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ImpairedFinancingReceivableAllowancesForCreditLosses" xlink:label="osbc_ImpairedFinancingReceivableAllowancesForCreditLosses_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="osbc_ImpairedFinancingReceivableAllowancesForCreditLosses_639216265578786317" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_ImpairedFinancingReceivableIncreaseDecreaseOfSpecificAllocationsWithinProvisionForLoanLosses" xlink:label="osbc_ImpairedFinancingReceivableIncreaseDecreaseOfSpecificAllocationsWithinProvisionForLoanLosses_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="osbc_ImpairedFinancingReceivableIncreaseDecreaseOfSpecificAllocationsWithinProvisionForLoanLosses_639216265578786317" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateAcquiredThroughForeclosure" xlink:label="us-gaap_RealEstateAcquiredThroughForeclosure_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="us-gaap_RealEstateAcquiredThroughForeclosure_639216265578786317" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_RealEstateGross" xlink:label="osbc_RealEstateGross_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="osbc_RealEstateGross_639216265578786317" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealEstateOwnedValuationAllowance" xlink:label="us-gaap_RealEstateOwnedValuationAllowance_639216265578786317" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_639216265578786317" xlink:to="us-gaap_RealEstateOwnedValuationAllowance_639216265578786317" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureFairValuesOfFinancialInstrumentsDetails" xlink:type="extended" xlink:title="99941301 - Disclosure - Fair Values of Financial Instruments (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" xlink:label="osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTable_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="osbc_FairValuesOfFinancialInstrumentsDisclosureAbstract" xlink:to="us-gaap_FairValueByBalanceSheetGroupingTable_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByBalanceSheetGroupingTable_639216265578816741" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis_639216265578816741" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578816741" xlink:to="us-gaap_FairValueInputsLevel1Member_639216265578816741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578816741" xlink:to="us-gaap_FairValueInputsLevel2Member_639216265578816741" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_639216265578816741" xlink:to="us-gaap_FairValueInputsLevel3Member_639216265578816741" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="us-gaap_FairValueByMeasurementBasisAxis_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByBalanceSheetGroupingTable_639216265578816741" xlink:to="us-gaap_FairValueByMeasurementBasisAxis_639216265578816741" order="2" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementBasisAxis_639216265578816741" xlink:to="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="us-gaap_CarryingReportedAmountFairValueDisclosureMember_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578816741" xlink:to="us-gaap_CarryingReportedAmountFairValueDisclosureMember_639216265578816741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="us-gaap_EstimateOfFairValueFairValueDisclosureMember_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PortionAtFairValueFairValueDisclosureMember_639216265578816741" xlink:to="us-gaap_EstimateOfFairValueFairValueDisclosureMember_639216265578816741" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:label="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByBalanceSheetGroupingTable_639216265578816741" xlink:to="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_639216265578816741" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract" xlink:label="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_639216265578816741" xlink:to="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndDueFromBanks" xlink:label="us-gaap_CashAndDueFromBanks_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_CashAndDueFromBanks_639216265578816741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestBearingDepositsInBanks" xlink:label="us-gaap_InterestBearingDepositsInBanks_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_InterestBearingDepositsInBanks_639216265578816741" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_639216265578816741" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:label="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_639216265578816741" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoansHeldForSaleFairValueDisclosure" xlink:label="us-gaap_LoansHeldForSaleFairValueDisclosure_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_LoansHeldForSaleFairValueDisclosure_639216265578816741" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoansReceivableFairValueDisclosure" xlink:label="us-gaap_LoansReceivableFairValueDisclosure_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_LoansReceivableFairValueDisclosure_639216265578816741" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ServicingAssetAtFairValueAmount" xlink:label="us-gaap_ServicingAssetAtFairValueAmount_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_ServicingAssetAtFairValueAmount_639216265578816741" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeAssets" xlink:label="us-gaap_DerivativeAssets_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_DerivativeAssets_639216265578816741" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InterestRateLockCommitmentsAndForwardContracts" xlink:label="osbc_InterestRateLockCommitmentsAndForwardContracts_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="osbc_InterestRateLockCommitmentsAndForwardContracts_639216265578816741" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestReceivable" xlink:label="us-gaap_InterestReceivable_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_InterestReceivable_639216265578816741" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract" xlink:label="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_639216265578816741" xlink:to="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoninterestBearingDepositLiabilities" xlink:label="us-gaap_NoninterestBearingDepositLiabilities_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_NoninterestBearingDepositLiabilities_639216265578816741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestBearingDepositLiabilities" xlink:label="us-gaap_InterestBearingDepositLiabilities_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_InterestBearingDepositLiabilities_639216265578816741" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure" xlink:label="us-gaap_SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure_639216265578816741" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherShortTermBorrowings" xlink:label="us-gaap_OtherShortTermBorrowings_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_OtherShortTermBorrowings_639216265578816741" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust" xlink:label="us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_639216265578816741" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations_639216265578816741" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NotesAndLoansPayable" xlink:label="us-gaap_NotesAndLoansPayable_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_NotesAndLoansPayable_639216265578816741" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilities" xlink:label="us-gaap_DerivativeLiabilities_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_DerivativeLiabilities_639216265578816741" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InterestRateLockCommitmentsAndForwardContractsLiabilities" xlink:label="osbc_InterestRateLockCommitmentsAndForwardContractsLiabilities_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="osbc_InterestRateLockCommitmentsAndForwardContractsLiabilities_639216265578816741" order="9" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_639216265578816741" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent_639216265578816741" order="10" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="2" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskDetails" xlink:type="extended" xlink:title="99941401 - Disclosure - Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationAxis" xlink:label="us-gaap_HedgingDesignationAxis_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" xlink:to="us-gaap_HedgingDesignationAxis_639216265578816741" order="1" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain" xlink:label="us-gaap_HedgingDesignationDomain_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_HedgingDesignationAxis_639216265578816741" xlink:to="us-gaap_HedgingDesignationDomain_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="us-gaap_DesignatedAsHedgingInstrumentMember_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_HedgingDesignationDomain_639216265578816741" xlink:to="us-gaap_DesignatedAsHedgingInstrumentMember_639216265578816741" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NondesignatedMember" xlink:label="us-gaap_NondesignatedMember_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_HedgingDesignationDomain_639216265578816741" xlink:to="us-gaap_NondesignatedMember_639216265578816741" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_639216265578816741" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentRiskAxis_639216265578816741" xlink:to="us-gaap_DerivativeContractTypeDomain_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateContractMember" xlink:label="us-gaap_InterestRateContractMember_639216265578816741" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578816741" xlink:to="us-gaap_InterestRateContractMember_639216265578816741" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember" xlink:label="us-gaap_InterestRateSwapMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578816741" xlink:to="us-gaap_InterestRateSwapMember_639216265578852177" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_DerivativeCommitmentsMember" xlink:label="osbc_DerivativeCommitmentsMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578816741" xlink:to="osbc_DerivativeCommitmentsMember_639216265578852177" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InterestRateLockCommitmentsAndForwardContractsMember" xlink:label="osbc_InterestRateLockCommitmentsAndForwardContractsMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578816741" xlink:to="osbc_InterestRateLockCommitmentsAndForwardContractsMember_639216265578852177" order="4" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherContractMember" xlink:label="us-gaap_OtherContractMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain_639216265578816741" xlink:to="us-gaap_OtherContractMember_639216265578852177" order="5" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_CounterpartyNameAxis" xlink:label="srt_CounterpartyNameAxis_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" xlink:to="srt_CounterpartyNameAxis_639216265578852177" order="3" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_CounterpartyNameAxis_639216265578852177" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_639216265578852177" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommercialLoanCustomersMember" xlink:label="osbc_CommercialLoanCustomersMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_639216265578852177" xlink:to="osbc_CommercialLoanCustomersMember_639216265578852177" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_OsbcAffiliatesMember" xlink:label="osbc_OsbcAffiliatesMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_639216265578852177" xlink:to="osbc_OsbcAffiliatesMember_639216265578852177" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_TwoFinancialInstitutionsMember" xlink:label="osbc_TwoFinancialInstitutionsMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain_639216265578852177" xlink:to="osbc_TwoFinancialInstitutionsMember_639216265578852177" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" xlink:to="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_639216265578852177" order="4" use="optional" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="us-gaap_HedgingRelationshipDomain_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_639216265578852177" xlink:to="us-gaap_HedgingRelationshipDomain_639216265578852177" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CashFlowHedgesOfCertainVariableRateCommercialAndCommercialRealEstateLoanPoolsMember" xlink:label="osbc_CashFlowHedgesOfCertainVariableRateCommercialAndCommercialRealEstateLoanPoolsMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_HedgingRelationshipDomain_639216265578852177" xlink:to="osbc_CashFlowHedgesOfCertainVariableRateCommercialAndCommercialRealEstateLoanPoolsMember_639216265578852177" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CashFlowHedgeOfJuniorSubordinatedDebenturesAndWasExecutedToPayFixedAndReceiveVariableRateCashFlowsMember" xlink:label="osbc_CashFlowHedgeOfJuniorSubordinatedDebenturesAndWasExecutedToPayFixedAndReceiveVariableRateCashFlowsMember_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_HedgingRelationshipDomain_639216265578852177" xlink:to="osbc_CashFlowHedgeOfJuniorSubordinatedDebenturesAndWasExecutedToPayFixedAndReceiveVariableRateCashFlowsMember_639216265578852177" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLineItems" xlink:label="us-gaap_DerivativeLineItems_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_639216265578816741" xlink:to="us-gaap_DerivativeLineItems_639216265578852177" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeNotionalAmount" xlink:label="us-gaap_DerivativeNotionalAmount_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="us-gaap_DerivativeNotionalAmount_639216265578852177" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_InterestRateCashFlowHedgeLossToBeReclassifiedDuringNext12MonthsNet" xlink:label="osbc_InterestRateCashFlowHedgeLossToBeReclassifiedDuringNext12MonthsNet_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="osbc_InterestRateCashFlowHedgeLossToBeReclassifiedDuringNext12MonthsNet_639216265578852177" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCollateralForBorrowedSecurities" xlink:label="us-gaap_CashCollateralForBorrowedSecurities_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="us-gaap_CashCollateralForBorrowedSecurities_639216265578852177" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_NumberOfFinancialInstitutionsInWhichCashCollateralPledged" xlink:label="osbc_NumberOfFinancialInstitutionsInWhichCashCollateralPledged_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="osbc_NumberOfFinancialInstitutionsInWhichCashCollateralPledged_639216265578852177" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecurities" xlink:label="us-gaap_DebtSecurities_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="us-gaap_DebtSecurities_639216265578852177" order="5" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld" xlink:label="us-gaap_DerivativeNumberOfInstrumentsHeld_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="us-gaap_DerivativeNumberOfInstrumentsHeld_639216265578852177" order="6" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashFlowHedgeDerivativeInstrumentAssetsAtFairValue" xlink:label="us-gaap_CashFlowHedgeDerivativeInstrumentAssetsAtFairValue_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="us-gaap_CashFlowHedgeDerivativeInstrumentAssetsAtFairValue_639216265578852177" order="7" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue" xlink:label="us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578852177" xlink:to="us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue_639216265578852177" order="8" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskEffectOfFairValueAndCashFlowHedgeAccountingDetails" xlink:type="extended" xlink:title="99941402 - Disclosure - Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk - Effect of Fair Value and Cash Flow Hedge Accounting (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract_636606688676700759" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet" xlink:label="us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract_636606688676700759" xlink:to="us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_639216265578852177" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_639216265578852177" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract_636606688676700759" xlink:to="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_639216265578852177" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureDerivativesHedgingActivitiesAndFinancialInstrumentsWithOffBalanceSheetRiskCommitmentsDetails" xlink:type="extended" xlink:title="99941403 - Disclosure - Derivatives, Hedging Activities and Financial Instruments with Off-Balance Sheet Risk - Commitments (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTable" xlink:label="us-gaap_DerivativeTable_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_DerivativeTable_639216265578873253" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_639216265578873253" xlink:to="us-gaap_FinancialInstrumentAxis_639216265578873253" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis_639216265578873253" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578873253" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_CommitmentsToExtendCreditToBorrowersMember" xlink:label="osbc_CommitmentsToExtendCreditToBorrowersMember_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578873253" xlink:to="osbc_CommitmentsToExtendCreditToBorrowersMember_639216265578873253" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnusedLinesOfCreditMember" xlink:label="us-gaap_UnusedLinesOfCreditMember_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_639216265578873253" xlink:to="us-gaap_UnusedLinesOfCreditMember_639216265578873253" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GuaranteeObligationsByNatureAxis" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_639216265578873253" xlink:to="us-gaap_GuaranteeObligationsByNatureAxis_639216265578873253" order="2" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:label="us-gaap_GuaranteeObligationsNatureDomain_639216265578873253" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GuaranteeObligationsByNatureAxis_639216265578873253" xlink:to="us-gaap_GuaranteeObligationsNatureDomain_639216265578873253" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialStandbyLetterOfCreditMember" xlink:label="us-gaap_FinancialStandbyLetterOfCreditMember_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GuaranteeObligationsNatureDomain_639216265578873253" xlink:to="us-gaap_FinancialStandbyLetterOfCreditMember_639216265578878644" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformanceGuaranteeMember" xlink:label="us-gaap_PerformanceGuaranteeMember_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GuaranteeObligationsNatureDomain_639216265578873253" xlink:to="us-gaap_PerformanceGuaranteeMember_639216265578878644" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnderlyingAssetClassAxis" xlink:label="us-gaap_UnderlyingAssetClassAxis_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_639216265578873253" xlink:to="us-gaap_UnderlyingAssetClassAxis_639216265578878644" order="3" use="optional" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnderlyingAssetClassDomain" xlink:label="us-gaap_UnderlyingAssetClassDomain_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_UnderlyingAssetClassAxis_639216265578878644" xlink:to="us-gaap_UnderlyingAssetClassDomain_639216265578878644" order="1" use="optional" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_FixedMember" xlink:label="osbc_FixedMember_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_UnderlyingAssetClassDomain_639216265578878644" xlink:to="osbc_FixedMember_639216265578878644" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_VariableMember" xlink:label="osbc_VariableMember_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_UnderlyingAssetClassDomain_639216265578878644" xlink:to="osbc_VariableMember_639216265578878644" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLineItems" xlink:label="us-gaap_DerivativeLineItems_639216265578878644" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeTable_639216265578873253" xlink:to="us-gaap_DerivativeLineItems_639216265578878644" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_639216265578883913" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578878644" xlink:to="us-gaap_LettersOfCreditOutstandingAmount_639216265578883913" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="4" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability" xlink:label="us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability_639216265578884398" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578878644" xlink:to="us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability_639216265578884398" order="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_AllowanceForCreditLossOnUnfundedCommitments" xlink:label="osbc_AllowanceForCreditLossOnUnfundedCommitments_639216265578884398" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578878644" xlink:to="osbc_AllowanceForCreditLossOnUnfundedCommitments_639216265578884398" order="3" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
    <loc xlink:type="locator" xlink:href="osbc-20260630.xsd#osbc_IncreaseDecreaseInAllowanceForCreditLossOnUnfundedCommitments" xlink:label="osbc_IncreaseDecreaseInAllowanceForCreditLossOnUnfundedCommitments_639216265578884398" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeLineItems_639216265578878644" xlink:to="osbc_IncreaseDecreaseInAllowanceForCreditLossOnUnfundedCommitments_639216265578884398" order="4" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" priority="3" />
  </presentationLink>
  <presentationLink xlink:role="http://www.oldsecond.com/role/DisclosureSegmentInformationDetails" xlink:type="extended" xlink:title="99941501 - Disclosure - Segment Information (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract_1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NumberOfReportableSegments" xlink:label="us-gaap_NumberOfReportableSegments_639216265578889934" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingAbstract_1" xlink:to="us-gaap_NumberOfReportableSegments_639216265578889934" order="1" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" priority="1" />
  </presentationLink>
  <presentationLink xlink:role="http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements" xlink:type="extended" xlink:title="995445 - Disclosure - Insider Trading Arrangements" xmlns="http://www.xbrl.org/2003/linkbase" />
</link:linkbase>
