<?xml version="1.0" encoding="US-ASCII"?>
<!-- Generated by Broadridge Transform (tm) - http://www.broadridge.com -->
<!-- Created: Wed Aug 05 14:14:50 UTC 2026 -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" 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" xmlns:xbrldt="http://xbrl.org/2005/xbrldt">
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ConsolidatedBalanceSheet" roleURI="http://www.yoursbfinancial.com/role/ConsolidatedBalanceSheet"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ConsolidatedBalanceSheet_Parentheticals" roleURI="http://www.yoursbfinancial.com/role/ConsolidatedBalanceSheet_Parentheticals"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ConsolidatedIncomeStatement" roleURI="http://www.yoursbfinancial.com/role/ConsolidatedIncomeStatement"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ConsolidatedComprehensiveIncome" roleURI="http://www.yoursbfinancial.com/role/ConsolidatedComprehensiveIncome"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShareholdersEquityType2or3" roleURI="http://www.yoursbfinancial.com/role/ShareholdersEquityType2or3"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShareholdersEquityType2or3_Parentheticals" roleURI="http://www.yoursbfinancial.com/role/ShareholdersEquityType2or3_Parentheticals"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ConsolidatedCashFlow" roleURI="http://www.yoursbfinancial.com/role/ConsolidatedCashFlow"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_BasisofPresentation" roleURI="http://www.yoursbfinancial.com/role/BasisofPresentation"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_EarningsPerShare" roleURI="http://www.yoursbfinancial.com/role/EarningsPerShare"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_BusinessCombinations" roleURI="http://www.yoursbfinancial.com/role/BusinessCombinations"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_AvailableforSaleSecurities" roleURI="http://www.yoursbfinancial.com/role/AvailableforSaleSecurities"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_LoansandAllowanceforCreditLosses" roleURI="http://www.yoursbfinancial.com/role/LoansandAllowanceforCreditLosses"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_Goodwill" roleURI="http://www.yoursbfinancial.com/role/Goodwill"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_MortgageServicingRights" roleURI="http://www.yoursbfinancial.com/role/MortgageServicingRights"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_DerivativeFinancialInstruments" roleURI="http://www.yoursbfinancial.com/role/DerivativeFinancialInstruments"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_Deposits" roleURI="http://www.yoursbfinancial.com/role/Deposits"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShortTermBorrowings" roleURI="http://www.yoursbfinancial.com/role/ShortTermBorrowings"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_FederalHomeLoanBankFHLBAdvances" roleURI="http://www.yoursbfinancial.com/role/FederalHomeLoanBankFHLBAdvances"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_TrustPreferredSecurities" roleURI="http://www.yoursbfinancial.com/role/TrustPreferredSecurities"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_SubordinatedDebt" roleURI="http://www.yoursbfinancial.com/role/SubordinatedDebt"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_DisclosuresAboutFairValueofAssetsandLiabilities" roleURI="http://www.yoursbfinancial.com/role/DisclosuresAboutFairValueofAssetsandLiabilities"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShareBasedCompensation" roleURI="http://www.yoursbfinancial.com/role/ShareBasedCompensation"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_OperatingSegments" roleURI="http://www.yoursbfinancial.com/role/OperatingSegments"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_GeneralLitigation" roleURI="http://www.yoursbfinancial.com/role/GeneralLitigation"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_AccountingPoliciesByPolicy" roleURI="http://www.yoursbfinancial.com/role/AccountingPoliciesByPolicy"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_EarningsPerShareTables" roleURI="http://www.yoursbfinancial.com/role/EarningsPerShareTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_BusinessCombinationsTables" roleURI="http://www.yoursbfinancial.com/role/BusinessCombinationsTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_AvailableforSaleSecuritiesTables" roleURI="http://www.yoursbfinancial.com/role/AvailableforSaleSecuritiesTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_LoansandAllowanceforCreditLossesTables" roleURI="http://www.yoursbfinancial.com/role/LoansandAllowanceforCreditLossesTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_GoodwillTables" roleURI="http://www.yoursbfinancial.com/role/GoodwillTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_MortgageServicingRightsTables" roleURI="http://www.yoursbfinancial.com/role/MortgageServicingRightsTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_DerivativeFinancialInstrumentsTables" roleURI="http://www.yoursbfinancial.com/role/DerivativeFinancialInstrumentsTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_DepositsTables" roleURI="http://www.yoursbfinancial.com/role/DepositsTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShortTermBorrowingsTables" roleURI="http://www.yoursbfinancial.com/role/ShortTermBorrowingsTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_FederalHomeLoanBankFHLBAdvancesTables" roleURI="http://www.yoursbfinancial.com/role/FederalHomeLoanBankFHLBAdvancesTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_DisclosuresAboutFairValueofAssetsandLiabilitiesTables" roleURI="http://www.yoursbfinancial.com/role/DisclosuresAboutFairValueofAssetsandLiabilitiesTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShareBasedCompensationTables" roleURI="http://www.yoursbfinancial.com/role/ShareBasedCompensationTables"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofBasicandDilutedEarningsPerShareTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofBasicandDilutedEarningsPerShareTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofAssetsChangestoValuationDeterminableatAcquisitionDateTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofAssetsChangestoValuationDeterminableatAcquisitionDateTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofAmortizedCostandFairValueswithGrossUnrealizedGainsandLossesTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofAmortizedCostandFairValueswithGrossUnrealizedGainsandLossesTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofAmortizedCostandFairValueofSecuritiesAvailableForSaleTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofAmortizedCostandFairValueofSecuritiesAvailableForSaleTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofSecuritieswithUnrealizedLossesTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofSecuritieswithUnrealizedLossesTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofCompositionoftheLoanPortfolioTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofCompositionoftheLoanPortfolioTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofActivityRelatedtotheACLTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofActivityRelatedtotheACLTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofPresentanAnalysisofCollateralDependentLoansTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofPresentanAnalysisofCollateralDependentLoansTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofLoanBalancesbyCreditQualityIndicatorsandGrossChargeoffsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofLoanBalancesbyCreditQualityIndicatorsandGrossChargeoffsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofCompanysLoanPortfolioAgingAnalysisTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofCompanysLoanPortfolioAgingAnalysisTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofCategoriesofNonaccrualLoansTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofCategoriesofNonaccrualLoansTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofACLforUnfundedLoanCommitmentsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofACLforUnfundedLoanCommitmentsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofGoodwillTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofGoodwillTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofMortgageServicingRightsCapitalizedandRelatedAmortizationTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofMortgageServicingRightsCapitalizedandRelatedAmortizationTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofNotionalAmountandFairValueoftheCompanysInterestRateSwapsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofNotionalAmountandFairValueoftheCompanysInterestRateSwapsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofConsolidatedStatementsofIncomeforNonHedgingDerivativeFinancialInstrumentsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofConsolidatedStatementsofIncomeforNonHedgingDerivativeFinancialInstrumentsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofOffsettingofFinancialAssetsandDerivativeAssetsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofOffsettingofFinancialAssetsandDerivativeAssetsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofMajorClassificationofDepositsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofMajorClassificationofDepositsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofMajorClassificationofDepositsTable_Parentheticals" roleURI="http://www.yoursbfinancial.com/role/ScheduleofMajorClassificationofDepositsTable_Parentheticals"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofShortTermBorrowingsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofShortTermBorrowingsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofAggregateAnnualMaturitiesofFHLBAdvancesTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofAggregateAnnualMaturitiesofFHLBAdvancesTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofFairValueMeasurementsRecognizedintheAccompanyingCondensedConsolidatedBalanceSheetsUsingSignificantUnobservableTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofFairValueMeasurementsRecognizedintheAccompanyingCondensedConsolidatedBalanceSheetsUsingSignificantUnobservableTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofMortgageServicingRightsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofMortgageServicingRightsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofEstimatedFairValuesoftheCompanysOtherFinancialInstrumentsTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofEstimatedFairValuesoftheCompanysOtherFinancialInstrumentsTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ScheduleofSummaryofRestrictedStockActivityTable" roleURI="http://www.yoursbfinancial.com/role/ScheduleofSummaryofRestrictedStockActivityTable"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_BusinessCombinationsDetails" roleURI="http://www.yoursbfinancial.com/role/BusinessCombinationsDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_AvailableforSaleSecuritiesDetails" roleURI="http://www.yoursbfinancial.com/role/AvailableforSaleSecuritiesDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_LoansandAllowanceforCreditLossesDetails" roleURI="http://www.yoursbfinancial.com/role/LoansandAllowanceforCreditLossesDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_GoodwillDetails" roleURI="http://www.yoursbfinancial.com/role/GoodwillDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_MortgageServicingRightsDetails" roleURI="http://www.yoursbfinancial.com/role/MortgageServicingRightsDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_DepositsDetails" roleURI="http://www.yoursbfinancial.com/role/DepositsDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShortTermBorrowingsDetails" roleURI="http://www.yoursbfinancial.com/role/ShortTermBorrowingsDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_FederalHomeLoanBankFHLBAdvancesDetails" roleURI="http://www.yoursbfinancial.com/role/FederalHomeLoanBankFHLBAdvancesDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_TrustPreferredSecuritiesDetails" roleURI="http://www.yoursbfinancial.com/role/TrustPreferredSecuritiesDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_SubordinatedDebtDetails" roleURI="http://www.yoursbfinancial.com/role/SubordinatedDebtDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_ShareBasedCompensationDetails" roleURI="http://www.yoursbfinancial.com/role/ShareBasedCompensationDetails"/>
  <roleRef xlink:type="simple" xlink:href="sbfg-20260630.xsd#sbfg_r_OperatingSegmentsDetails" roleURI="http://www.yoursbfinancial.com/role/OperatingSegmentsDetails"/>
  <roleRef xlink:type="simple" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-roles-2026.xsd#eedm1" roleURI="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member"/>
  <arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all"/>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ConsolidatedBalanceSheet" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndDueFromBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndDueFromBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CashAndDueFromBanks" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestBearingDepositsInBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositsInBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_InterestBearingDepositsInBanks" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecurities" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesAndLoansReceivableNetNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_NotesAndLoansReceivableNetNoncurrent" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ForeclosedAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeclosedAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_ForeclosedAssets" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestReceivable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_InterestReceivable" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Goodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_Goodwill" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashSurrenderValueOfLifeInsurance" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashSurrenderValueOfLifeInsurance"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CashSurrenderValueOfLifeInsurance" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_MortgageServicingRights" xlink:href="sbfg-20260630.xsd#sbfg_MortgageServicingRights"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="sbfg_MortgageServicingRights" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_OtherAssets" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_Assets" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoninterestBearingDepositLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_NoninterestBearingDepositLiabilities" order="15" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestBearingDepositLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositLiabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_InterestBearingDepositLiabilities" order="16" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsSavingsDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsSavingsDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_DepositsSavingsDeposits" order="17" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsMoneyMarketDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsMoneyMarketDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_DepositsMoneyMarketDeposits" order="18" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TimeDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_TimeDeposits" order="19" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Deposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Deposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_Deposits" order="20" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase" order="21" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdvancesFromFederalHomeLoanBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdvancesFromFederalHomeLoanBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AdvancesFromFederalHomeLoanBanks" order="22" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLongTermDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_OtherLongTermDebt" order="23" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_SubordinatedDebtNetOfIssuanceCosts" xlink:href="sbfg-20260630.xsd#sbfg_SubordinatedDebtNetOfIssuanceCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="sbfg_SubordinatedDebtNetOfIssuanceCosts" order="24" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPayableCurrentAndNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent" order="25" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_OtherLiabilities" order="26" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Liabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_Liabilities" order="27" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommitmentsAndContingencies" order="28" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockValue" order="29" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockValue" order="30" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AdditionalPaidInCapital" order="31" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="32" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="33" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TreasuryStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_TreasuryStockValue" order="34" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StockholdersEquity" order="35" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" order="36" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ConsolidatedBalanceSheet_Parentheticals" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockNoParValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockNoParValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockNoParValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockNoParValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockNoParValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockNoParValue" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesAuthorized" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommonStockSharesIssued" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TreasuryStockCommonShares" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_TreasuryStockCommonShares" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ConsolidatedIncomeStatement" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementAbstract"/>
    <loc xlink:type="locator" xlink:label="sbfg_InterestIncomeLoanTaxable" xlink:href="sbfg-20260630.xsd#sbfg_InterestIncomeLoanTaxable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="sbfg_InterestIncomeLoanTaxable" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_InterestIncomeLoanTaxExempt" xlink:href="sbfg-20260630.xsd#sbfg_InterestIncomeLoanTaxExempt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="sbfg_InterestIncomeLoanTaxExempt" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeSecuritiesTaxable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeSecuritiesTaxable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeSecuritiesTaxable" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeSecuritiesTaxExempt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeSecuritiesTaxExempt" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeOther" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOther"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeOther" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeOperating" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOperating"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeOperating" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestExpenseDeposits" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseSecuritiesSoldUnderAgreementsToRepurchase" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseSecuritiesSoldUnderAgreementsToRepurchase"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestExpenseSecuritiesSoldUnderAgreementsToRepurchase" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseTrustPreferredSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseTrustPreferredSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestExpenseTrustPreferredSecurities" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseSubordinatedNotesAndDebentures" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseSubordinatedNotesAndDebentures"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestExpenseSubordinatedNotesAndDebentures" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseOperating" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseOperating"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestExpenseOperating" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeExpenseNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeExpenseNet" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForLoanLossesExpensed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ProvisionForLoanLossesExpensed" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_ProvisionForUnfundedCommitments" xlink:href="sbfg-20260630.xsd#sbfg_ProvisionForUnfundedCommitments"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="sbfg_ProvisionForUnfundedCommitments" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForLoanLeaseAndOtherLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ProvisionForLoanLeaseAndOtherLosses" order="15" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" order="16" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WealthManagementFees" xlink:href="sbfg-20260630.xsd#sbfg_WealthManagementFees"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="sbfg_WealthManagementFees" order="17" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CustomerServiceFees" xlink:href="sbfg-20260630.xsd#sbfg_CustomerServiceFees"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="sbfg_CustomerServiceFees" order="18" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfMortgageLoans" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfMortgageLoans"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_GainLossOnSaleOfMortgageLoans" order="19" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_MortgageLoanServicingFees" xlink:href="sbfg-20260630.xsd#sbfg_MortgageLoanServicingFees"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="sbfg_MortgageLoanServicingFees" order="20" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainLossOnDispositionOfOtherFinancialAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnDispositionOfOtherFinancialAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_GainLossOnDispositionOfOtherFinancialAssets" order="21" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BankOwnedLifeInsuranceIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BankOwnedLifeInsuranceIncome"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_BankOwnedLifeInsuranceIncome" order="22" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfOtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfOtherAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_GainLossOnSaleOfOtherAssets" order="23" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoninterestIncomeOtherOperatingIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncomeOtherOperatingIncome"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NoninterestIncomeOtherOperatingIncome" order="24" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoninterestIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncome"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NoninterestIncome" order="25" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SalariesAndWages" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SalariesAndWages"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_SalariesAndWages" order="26" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OccupancyNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OccupancyNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_OccupancyNet" order="27" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquipmentExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquipmentExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EquipmentExpense" order="28" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InformationTechnologyAndDataProcessing" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_InformationTechnologyAndDataProcessing" order="29" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProfessionalFees" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_ProfessionalFees" order="30" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MarketingExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketingExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_MarketingExpense" order="31" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Communication" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Communication"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_Communication" order="32" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PostageExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PostageExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_PostageExpense" order="33" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TaxesExcludingIncomeAndExciseTaxes" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxesExcludingIncomeAndExciseTaxes"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_TaxesExcludingIncomeAndExciseTaxes" order="34" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LaborAndRelatedExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_LaborAndRelatedExpense" order="35" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherNoninterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNoninterestExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_OtherNoninterestExpense" order="36" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoninterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NoninterestExpense" order="37" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="38" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="39" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_NetIncomeLoss" order="40" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EarningsPerShareBasic" order="41" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" order="42" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" order="43" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" order="44" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ConsolidatedComprehensiveIncome" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_NetIncomeLoss" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="us-gaap_ComprehensiveIncomeNetOfTax" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShareholdersEquityType2or3" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AdditionalPaidInCapitalMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_RetainedEarningsMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TreasuryStockCommonMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_TreasuryStockCommonMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquity" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DividendsCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DividendsCommonStock" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RestrictedStockExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RestrictedStockExpense" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShareholdersEquityType2or3_Parentheticals" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfStockholdersEquityAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareCashPaid"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_CommonStockDividendsPerShareCashPaid" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ConsolidatedCashFlow" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetIncomeLoss" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepreciationDepletionAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_DepreciationDepletionAndAmortization" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForOtherCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForOtherCreditLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProvisionForOtherCreditLosses" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_AmortizationOfFinancingCostsAndDiscounts" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AmortizationOfIntangibleAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_AmortizationOfIntangibleAssets" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AmortizationOfMortgageServicingRightsMSRs" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfMortgageServicingRightsMSRs"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_AmortizationOfMortgageServicingRightsMSRs" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageServicingRightsMSRImpairmentRecovery" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageServicingRightsMSRImpairmentRecovery"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_MortgageServicingRightsMSRImpairmentRecovery" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfLoansHeldForSale" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfLoansHeldForSale"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfLoansHeldForSale" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsToPurchaseLoansHeldForSale" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToPurchaseLoansHeldForSale"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsToPurchaseLoansHeldForSale" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainLossOnSalesOfLoansNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_GainLossOnSalesOfLoansNet" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainLossOnDispositionOfAssets1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnDispositionOfAssets1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_GainLossOnDispositionOfAssets1" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets" order="13" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInInterestPayableNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInInterestPayableNet" order="14" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="15" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" order="16" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsForProceedsFromOtherInterestEarningAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromOtherInterestEarningAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsForProceedsFromOtherInterestEarningAssets" order="17" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromPaymentsForInInterestBearingDepositsInBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromPaymentsForInInterestBearingDepositsInBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromPaymentsForInInterestBearingDepositsInBanks" order="18" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" order="19" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt" order="20" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsForProceedsFromLoansAndLeases" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromLoansAndLeases"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsForProceedsFromLoansAndLeases" order="21" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireProductiveAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsToAcquireProductiveAssets" order="22" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" order="23" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsForProceedsFromLifeInsurancePolicies" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromLifeInsurancePolicies"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsForProceedsFromLifeInsurancePolicies" order="24" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireFederalHomeLoanBankStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireFederalHomeLoanBankStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsToAcquireFederalHomeLoanBankStock" order="25" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock" order="26" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfForeclosedAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfForeclosedAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfForeclosedAssets" order="27" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" order="28" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities" order="29" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInDemandDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDemandDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInDemandDeposits" order="30" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInTimeDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInTimeDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInTimeDeposits" order="31" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet" order="32" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RepaymentsOfBankDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfBankDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_RepaymentsOfBankDebt" order="33" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsForRepurchaseOfCommonStock" order="34" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfDividendsCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_PaymentsOfDividendsCommonStock" order="35" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" order="36" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" order="37" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" order="38" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestPaidNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPaidNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_InterestPaidNet" order="39" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxesPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxesPaid"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_IncomeTaxesPaid" order="40" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TransferOfLoansToLoansHeldForSale" xlink:href="sbfg-20260630.xsd#sbfg_TransferOfLoansToLoansHeldForSale"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="sbfg_TransferOfLoansToLoansHeldForSale" order="41" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TransferOfLoansToForeclosedAssets" xlink:href="sbfg-20260630.xsd#sbfg_TransferOfLoansToForeclosedAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="sbfg_TransferOfLoansToForeclosedAssets" order="42" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueOfAssetsAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueOfAssetsAcquired"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_FairValueOfAssetsAcquired" order="43" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CashPaidInAcquisition" xlink:href="sbfg-20260630.xsd#sbfg_CashPaidInAcquisition"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="sbfg_CashPaidInAcquisition" order="44" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_LiabilitiesAssumed" xlink:href="sbfg-20260630.xsd#sbfg_LiabilitiesAssumed"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="sbfg_LiabilitiesAssumed" order="45" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/BasisofPresentation" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/EarningsPerShare" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/BusinessCombinations" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/AvailableforSaleSecurities" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/LoansandAllowanceforCreditLosses" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_NotesReceivableNetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNetAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LoansNotesTradeAndOtherReceivablesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansNotesTradeAndOtherReceivablesDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="us-gaap_LoansNotesTradeAndOtherReceivablesDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/Goodwill" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DisclosureTextBlockSupplementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisclosureTextBlockSupplementAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DisclosureTextBlockSupplementAbstract" xlink:to="us-gaap_GoodwillDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/MortgageServicingRights" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageNotesPayableDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageNotesPayableDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_MortgageNotesPayableDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/DerivativeFinancialInstruments" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/Deposits" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepositLiabilitiesDisclosuresTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositLiabilitiesDisclosuresTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DepositsAbstract" xlink:to="us-gaap_DepositLiabilitiesDisclosuresTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShortTermBorrowings" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermBorrowingsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowingsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermBorrowingsAbstract" xlink:to="us-gaap_ShortTermDebtTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/FederalHomeLoanBankFHLBAdvances" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBanksAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBanksAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBanksAbstract" xlink:to="us-gaap_FederalHomeLoanBankAdvancesDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/TrustPreferredSecurities" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="sbfg_TrustPreferredSecuritiesAbstract" xlink:href="sbfg-20260630.xsd#sbfg_TrustPreferredSecuritiesAbstract"/>
    <loc xlink:type="locator" xlink:label="sbfg_TrustPreferredSecuritiesTextBlock" xlink:href="sbfg-20260630.xsd#sbfg_TrustPreferredSecuritiesTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_TrustPreferredSecuritiesAbstract" xlink:to="sbfg_TrustPreferredSecuritiesTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/SubordinatedDebt" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_SubordinatedLongtermDebtCurrentAndNoncurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubordinatedLongtermDebtCurrentAndNoncurrentAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubordinatedBorrowingsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubordinatedBorrowingsDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedLongtermDebtCurrentAndNoncurrentAbstract" xlink:to="us-gaap_SubordinatedBorrowingsDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/DisclosuresAboutFairValueofAssetsandLiabilities" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosuresTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShareBasedCompensation" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/OperatingSegments" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/GeneralLitigation" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/AccountingPoliciesByPolicy" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <loc xlink:type="locator" xlink:label="sbfg_AccountingStandardsNotYetAdoptedPolicyTextBlock" xlink:href="sbfg-20260630.xsd#sbfg_AccountingStandardsNotYetAdoptedPolicyTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="sbfg_AccountingStandardsNotYetAdoptedPolicyTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/EarningsPerShareTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/BusinessCombinationsTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/AvailableforSaleSecuritiesTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HeldToMaturitySecuritiesTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_HeldToMaturitySecuritiesTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/LoansandAllowanceforCreditLossesTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_NotesReceivableNetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNetAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_ScheduleOfCollateraldependentLoansTableTextBlock" xlink:href="sbfg-20260630.xsd#sbfg_ScheduleOfCollateraldependentLoansTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="sbfg_ScheduleOfCollateraldependentLoansTableTextBlock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PastDueFinancingReceivablesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PastDueFinancingReceivablesTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="us-gaap_PastDueFinancingReceivablesTableTextBlock" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_ScheduleOfCategoriesOfNonaccrualLoansTableTextBlock" xlink:href="sbfg-20260630.xsd#sbfg_ScheduleOfCategoriesOfNonaccrualLoansTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="sbfg_ScheduleOfCategoriesOfNonaccrualLoansTableTextBlock" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_ScheduleOfAccumulatedCreditLossesACLForUnfundedLoanCommitmentsTableTextBlock" xlink:href="sbfg-20260630.xsd#sbfg_ScheduleOfAccumulatedCreditLossesACLForUnfundedLoanCommitmentsTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NotesReceivableNetAbstract" xlink:to="sbfg_ScheduleOfAccumulatedCreditLossesACLForUnfundedLoanCommitmentsTableTextBlock" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/GoodwillTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DisclosureTextBlockSupplementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisclosureTextBlockSupplementAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGoodwillTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DisclosureTextBlockSupplementAbstract" xlink:to="us-gaap_ScheduleOfGoodwillTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/MortgageServicingRightsTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfServicingAssetsAtAmortizedValueTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfServicingAssetsAtAmortizedValueTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_ScheduleOfServicingAssetsAtAmortizedValueTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/DerivativeFinancialInstrumentsTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_ScheduleOfCondensedFinancialStatementsTableTextBlock" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfCondensedFinancialStatementsTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="srt_ScheduleOfCondensedFinancialStatementsTableTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfDerivativeAssetsAtFairValueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfDerivativeAssetsAtFairValueTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_ScheduleOfDerivativeAssetsAtFairValueTableTextBlock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:to="us-gaap_ScheduleOfDerivativeLiabilitiesAtFairValueTableTextBlock" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/DepositsTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByBalanceSheetGroupingTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DepositsAbstract" xlink:to="us-gaap_FairValueByBalanceSheetGroupingTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShortTermBorrowingsTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermBorrowingsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowingsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShortTermDebtTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermBorrowingsAbstract" xlink:to="us-gaap_ScheduleOfShortTermDebtTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/FederalHomeLoanBankFHLBAdvancesTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBanksAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBanksAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfFederalHomeLoanBankAdvancesByBranchOfFHLBBankTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFederalHomeLoanBankAdvancesByBranchOfFHLBBankTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBanksAbstract" xlink:to="us-gaap_ScheduleOfFederalHomeLoanBankAdvancesByBranchOfFHLBBankTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/DisclosuresAboutFairValueofAssetsandLiabilitiesTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosuresAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsMeasuredOnNonrecurringBasisTextBlock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringAndNonrecurringBasisTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringAndNonrecurringBasisTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringAndNonrecurringBasisTableTextBlock" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShareBasedCompensationTables" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationAbstract" xlink:to="us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofBasicandDilutedEarningsPerShareTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasicTwoClassMethodAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DistributedEarnings" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DistributedEarnings"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_DistributedEarnings" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_NetEarningsAllocatedToParticipatingSecurities" xlink:href="sbfg-20260630.xsd#sbfg_NetEarningsAllocatedToParticipatingSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="sbfg_NetEarningsAllocatedToParticipatingSecurities" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_NetIncomeAllocatedToCommonSharesAndParticipatingSecurities" xlink:href="sbfg-20260630.xsd#sbfg_NetIncomeAllocatedToCommonSharesAndParticipatingSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="sbfg_NetIncomeAllocatedToCommonSharesAndParticipatingSecurities" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_EarningsPerShareBasic" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicTwoClassMethodAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" order="9" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofAssetsChangestoValuationDeterminableatAcquisitionDateTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:href="sbfg-20260630.xsd#sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationMember" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="sbfg_BusinessCombinationMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInvestmentSecurities" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInvestmentSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInvestmentSecurities" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedFederalReserveAndFederalHomeLoanBankStock" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedFederalReserveAndFederalHomeLoanBankStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedFederalReserveAndFederalHomeLoanBankStock" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansHeldForInvestment" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansHeldForInvestment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansHeldForInvestment" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedGoodwill" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedGoodwill"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedGoodwill" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeposits" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="sbfg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeposits" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_ScheduleOfAssetsChangesToValuationDeterminableAtAcquisitionDateLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" order="12" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofAmortizedCostandFairValueswithGrossUnrealizedGainsandLossesTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtSecuritiesAvailableForSaleTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USTreasuryAndGovernmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_USTreasuryAndGovernmentMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageBackedSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageBackedSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_MortgageBackedSecuritiesMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CorporateBondSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_CorporateBondSecuritiesMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecurities" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofAmortizedCostandFairValueofSecuritiesAvailableForSaleTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfHeldToMaturitySecuritiesTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_AmortizedCostMember" xlink:href="sbfg-20260630.xsd#sbfg_AmortizedCostMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_AmortizedCostMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_FairValueMember" xlink:href="sbfg-20260630.xsd#sbfg_FairValueMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_FairValueMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecurities" order="13" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofSecuritieswithUnrealizedLossesTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USTreasuryAndGovernmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_USTreasuryAndGovernmentMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageBackedSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageBackedSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_MortgageBackedSecuritiesMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllOtherCorporateBondsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllOtherCorporateBondsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_AllOtherCorporateBondsMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_NumberOfSecurities" xlink:href="sbfg-20260630.xsd#sbfg_NumberOfSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="sbfg_NumberOfSecurities" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofCompositionoftheLoanPortfolioTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:to="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesByIndustryAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable" xlink:to="us-gaap_EquitySecuritiesByIndustryAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialAndIndustrialSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialAndIndustrialSectorMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialRealEstateMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AgriculturalSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgriculturalSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_AgriculturalSectorMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResidentialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResidentialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ResidentialRealEstateMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_HomeEquityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HomeEquityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_HomeEquityMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConsumerSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ConsumerSectorMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesReceivableGross" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:to="us-gaap_NotesReceivableGross" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLosses" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesReceivableNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountsNotesAndLoansReceivableLineItems" xlink:to="us-gaap_NotesReceivableNet" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofActivityRelatedtotheACLTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:to="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesByIndustryAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable" xlink:to="us-gaap_EquitySecuritiesByIndustryAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialAndIndustrialSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialAndIndustrialSectorMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialRealEstateMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AgriculturalSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgriculturalSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_AgriculturalSectorMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResidentialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResidentialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ResidentialRealEstateMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_HomeEquityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HomeEquityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_HomeEquityMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConsumerSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ConsumerSectorMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLosses" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_InitialAllowanceForCreditLossesOnAcquiredPCDLoans" xlink:href="sbfg-20260630.xsd#sbfg_InitialAllowanceForCreditLossesOnAcquiredPCDLoans"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:to="sbfg_InitialAllowanceForCreditLossesOnAcquiredPCDLoans" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForOtherLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForOtherLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SecuritiesBorrowedAllowanceForCreditLossLineItems" xlink:to="us-gaap_ProvisionForOtherLosses" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofPresentanAnalysisofCollateralDependentLoansTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_RealEstateLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealEstateLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_LoansandAllowanceforCreditLossesScheduleofPresentanAnalysisofCollateralDependentLoansDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_LoansandAllowanceforCreditLossesScheduleofPresentanAnalysisofCollateralDependentLoansDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_RealEstateLineItems" xlink:to="sbfg_LoansandAllowanceforCreditLossesScheduleofPresentanAnalysisofCollateralDependentLoansDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CollateralAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_LoansandAllowanceforCreditLossesScheduleofPresentanAnalysisofCollateralDependentLoansDetailsTable" xlink:to="us-gaap_CollateralAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CollateralDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CollateralAxis" xlink:to="us-gaap_CollateralDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CollateralDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_CollateralAxis" xlink:to="us-gaap_CollateralDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesByIndustryAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_LoansandAllowanceforCreditLossesScheduleofPresentanAnalysisofCollateralDependentLoansDetailsTable" xlink:to="us-gaap_EquitySecuritiesByIndustryAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollateralDomain" xlink:to="us-gaap_RealEstateMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_OtherMember" xlink:href="sbfg-20260630.xsd#sbfg_OtherMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CollateralDomain" xlink:to="sbfg_OtherMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialAndIndustrialSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialAndIndustrialSectorMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialRealEstateMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResidentialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResidentialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ResidentialRealEstateMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RealEstateInvestments" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealEstateInvestments"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RealEstateLineItems" xlink:to="us-gaap_RealEstateInvestments" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForLoanAndLeaseLossesRealEstate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForLoanAndLeaseLossesRealEstate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RealEstateLineItems" xlink:to="us-gaap_AllowanceForLoanAndLeaseLossesRealEstate" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofLoanBalancesbyCreditQualityIndicatorsandGrossChargeoffsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InternalCreditAssessmentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable" xlink:to="us-gaap_InternalCreditAssessmentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InternalCreditAssessmentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_InternalCreditAssessmentAxis" xlink:to="us-gaap_InternalCreditAssessmentDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InternalCreditAssessmentDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_InternalCreditAssessmentAxis" xlink:to="us-gaap_InternalCreditAssessmentDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesByIndustryAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable" xlink:to="us-gaap_EquitySecuritiesByIndustryAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PassMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PassMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InternalCreditAssessmentDomain" xlink:to="us-gaap_PassMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SpecialMentionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SpecialMentionMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InternalCreditAssessmentDomain" xlink:to="us-gaap_SpecialMentionMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubstandardMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubstandardMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InternalCreditAssessmentDomain" xlink:to="us-gaap_SubstandardMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DoubtfulMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DoubtfulMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InternalCreditAssessmentDomain" xlink:to="us-gaap_DoubtfulMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_LossMember" xlink:href="sbfg-20260630.xsd#sbfg_LossMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InternalCreditAssessmentDomain" xlink:to="sbfg_LossMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CurrentPeriodGrossChargeoffsMember" xlink:href="sbfg-20260630.xsd#sbfg_CurrentPeriodGrossChargeoffsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_InternalCreditAssessmentDomain" xlink:to="sbfg_CurrentPeriodGrossChargeoffsMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialAndIndustrialSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialAndIndustrialSectorMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CommercialRealEstateOwnerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_CommercialRealEstateOwnerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_CommercialRealEstateOwnerOccupiedMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AgriculturalSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgriculturalSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_AgriculturalSectorMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResidentialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResidentialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ResidentialRealEstateMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_HomeEquityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HomeEquityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_HomeEquityMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConsumerSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ConsumerSectorMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TotalLoansMember" xlink:href="sbfg-20260630.xsd#sbfg_TotalLoansMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_TotalLoansMember" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_FinancingReceivableYearSixOriginatedFiveYearsbeforeCurrentFiscalYear" xlink:href="sbfg-20260630.xsd#sbfg_FinancingReceivableYearSixOriginatedFiveYearsbeforeCurrentFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="sbfg_FinancingReceivableYearSixOriginatedFiveYearsbeforeCurrentFiscalYear" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_FinancingReceivableOriginatedSixOrMoreYearsBeforeLatestFiscalYear" xlink:href="sbfg-20260630.xsd#sbfg_FinancingReceivableOriginatedSixOrMoreYearsBeforeLatestFiscalYear"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="sbfg_FinancingReceivableOriginatedSixOrMoreYearsBeforeLatestFiscalYear" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRevolving" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRevolving"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableRevolving" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRevolvingConvertedToTermLoan" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRevolvingConvertedToTermLoan"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_FinancingReceivableRevolvingConvertedToTermLoan" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesReceivableNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentLineItems" xlink:to="us-gaap_NotesReceivableNet" order="9" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofCompanysLoanPortfolioAgingAnalysisTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfFinancingReceivablesPastDueTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFinancingReceivablesPastDueTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:to="us-gaap_ScheduleOfFinancingReceivablesPastDueTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueAxis" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivablesPeriodPastDueDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueAxis" xlink:to="us-gaap_FinancingReceivablesPeriodPastDueDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesByIndustryAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfFinancingReceivablesPastDueTable" xlink:to="us-gaap_EquitySecuritiesByIndustryAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivables30To59DaysPastDueMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivables30To59DaysPastDueMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:to="us-gaap_FinancingReceivables30To59DaysPastDueMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivables60To89DaysPastDueMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivables60To89DaysPastDueMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:to="us-gaap_FinancingReceivables60To89DaysPastDueMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:to="us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialAssetPastDueMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetPastDueMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivablesPeriodPastDueDomain" xlink:to="us-gaap_FinancialAssetPastDueMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialAndIndustrialSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialAndIndustrialSectorMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CommercialRealEstateOwnerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_CommercialRealEstateOwnerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_CommercialRealEstateOwnerOccupiedMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AgriculturalSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgriculturalSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_AgriculturalSectorMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResidentialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResidentialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ResidentialRealEstateMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_HomeEquityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HomeEquityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_HomeEquityMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConsumerSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ConsumerSectorMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:to="us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesAndLoansReceivableNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesAndLoansReceivableNetCurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:to="us-gaap_NotesAndLoansReceivableNetCurrent" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesAndLoansReceivableNetNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems" xlink:to="us-gaap_NotesAndLoansReceivableNetNoncurrent" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofCategoriesofNonaccrualLoansTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableNonaccrualStatusLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableNonaccrualStatusLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_LoansandAllowanceforCreditLossesScheduleofCategoriesofNonaccrualLoansDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_LoansandAllowanceforCreditLossesScheduleofCategoriesofNonaccrualLoansDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FinancingReceivableNonaccrualStatusLineItems" xlink:to="sbfg_LoansandAllowanceforCreditLossesScheduleofCategoriesofNonaccrualLoansDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesByIndustryAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_LoansandAllowanceforCreditLossesScheduleofCategoriesofNonaccrualLoansDetailsTable" xlink:to="us-gaap_EquitySecuritiesByIndustryAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesIndustryMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_EquitySecuritiesByIndustryAxis" xlink:to="us-gaap_EquitySecuritiesIndustryMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommercialAndIndustrialSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_CommercialAndIndustrialSectorMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CommercialRealEstateOwnerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_CommercialRealEstateOwnerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_CommercialRealEstateOwnerOccupiedMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" xlink:href="sbfg-20260630.xsd#sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="sbfg_WithNoRelatedAllowanceRecordedCommercialRealEstateNonownerOccupiedMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AgriculturalSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AgriculturalSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_AgriculturalSectorMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ResidentialRealEstateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResidentialRealEstateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ResidentialRealEstateMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_HomeEquityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HomeEquityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_HomeEquityMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConsumerSectorMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerSectorMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquitySecuritiesIndustryMember" xlink:to="us-gaap_ConsumerSectorMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableNonaccrualNoAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableNonaccrualNoAllowance"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableNonaccrualStatusLineItems" xlink:to="us-gaap_FinancingReceivableNonaccrualNoAllowance" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableNonaccrualStatusLineItems" xlink:to="us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableNonaccrualStatusLineItems" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofACLforUnfundedLoanCommitmentsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_OtherCommitmentsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_LoansandAllowanceforCreditLossesScheduleofACLforUnfundedLoanCommitmentsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_LoansandAllowanceforCreditLossesScheduleofACLforUnfundedLoanCommitmentsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="sbfg_LoansandAllowanceforCreditLossesScheduleofACLforUnfundedLoanCommitmentsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_LoansandAllowanceforCreditLossesScheduleofACLforUnfundedLoanCommitmentsDetailsTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_UnfundedLoanCommitmentsMember" xlink:href="sbfg-20260630.xsd#sbfg_UnfundedLoanCommitmentsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_UnfundedLoanCommitmentsMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_FinancingReceivableAllowanceForCreditLosses" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_AdjustmentForAcquiredLoans" xlink:href="sbfg-20260630.xsd#sbfg_AdjustmentForAcquiredLoans"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="sbfg_AdjustmentForAcquiredLoans" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForOtherCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForOtherCreditLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_ProvisionForOtherCreditLosses" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofGoodwillTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillImpairedAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillImpairedAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Goodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_GoodwillImpairedAbstract" xlink:to="us-gaap_Goodwill" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_GoodwillImpairedAbstract" xlink:to="us-gaap_GoodwillAcquiredDuringPeriod" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofMortgageServicingRightsCapitalizedandRelatedAmortizationTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingAbstract"/>
    <loc xlink:type="locator" xlink:label="sbfg_MortgageServicingRights" xlink:href="sbfg-20260630.xsd#sbfg_MortgageServicingRights"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="sbfg_MortgageServicingRights" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_MortgageServicingRightsCapitalizedDuringThePeriod" xlink:href="sbfg-20260630.xsd#sbfg_MortgageServicingRightsCapitalizedDuringThePeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="sbfg_MortgageServicingRightsCapitalizedDuringThePeriod" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ServicingAssetAtAmortizedValueAmortization1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtAmortizedValueAmortization1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="us-gaap_ServicingAssetAtAmortizedValueAmortization1" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ServicingAssetAtAmortizedValueValuationAllowance" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtAmortizedValueValuationAllowance"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="us-gaap_ServicingAssetAtAmortizedValueValuationAllowance" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="us-gaap_ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ValuationAllowanceForImpairmentOfRecognizedServicingAssetsPeriodIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationAllowanceForImpairmentOfRecognizedServicingAssetsPeriodIncreaseDecrease"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="us-gaap_ValuationAllowanceForImpairmentOfRecognizedServicingAssetsPeriodIncreaseDecrease" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ServicingAssetAtAmortizedValueFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtAmortizedValueFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingAbstract" xlink:to="us-gaap_ServicingAssetAtAmortizedValueFairValue" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofNotionalAmountandFairValueoftheCompanysInterestRateSwapsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems" xlink:to="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_InterestRateSwapsAssociatedWithLoansMember" xlink:href="sbfg-20260630.xsd#sbfg_InterestRateSwapsAssociatedWithLoansMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="sbfg_InterestRateSwapsAssociatedWithLoansMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestRateLockCommitmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateLockCommitmentsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_InterestRateLockCommitmentsMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ForwardContractsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForwardContractsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_ForwardContractsMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeAssetNotionalAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems" xlink:to="us-gaap_DerivativeAssetNotionalAmount" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeAsset" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilityNotionalAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems" xlink:to="us-gaap_DerivativeLiabilityNotionalAmount" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeLiability" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofConsolidatedStatementsofIncomeforNonHedgingDerivativeFinancialInstrumentsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="srt_CondensedIncomeStatementsCaptionsLineItems" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CondensedIncomeStatementsCaptionsLineItems"/>
    <loc xlink:type="locator" xlink:label="srt_ScheduleOfCondensedFinancialStatementsTable" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfCondensedFinancialStatementsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="srt_CondensedIncomeStatementsCaptionsLineItems" xlink:to="srt_ScheduleOfCondensedFinancialStatementsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="srt_ScheduleOfCondensedFinancialStatementsTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestRateSwapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_InterestRateSwapMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestRateLockCommitmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateLockCommitmentsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_InterestRateLockCommitmentsMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ForwardContractsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForwardContractsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_ForwardContractsMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_DescriptionOfLocationOfGainLossOnInterestRateDerivativeOnStatementOfIncomeClassification" xlink:href="sbfg-20260630.xsd#sbfg_DescriptionOfLocationOfGainLossOnInterestRateDerivativeOnStatementOfIncomeClassification"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_CondensedIncomeStatementsCaptionsLineItems" xlink:to="sbfg_DescriptionOfLocationOfGainLossOnInterestRateDerivativeOnStatementOfIncomeClassification" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeGainLossOnDerivativeNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_CondensedIncomeStatementsCaptionsLineItems" xlink:to="us-gaap_DerivativeGainLossOnDerivativeNet" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofOffsettingofFinancialAssetsandDerivativeAssetsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialAssetsandDerivativeAssetsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialAssetsandDerivativeAssetsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialAssetsandDerivativeAssetsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialAssetsandDerivativeAssetsDetailsTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestRateSwapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_InterestRateSwapMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeAsset" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeCollateralObligationToReturnCash" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeCollateralObligationToReturnCash"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_DerivativeCollateralObligationToReturnCash" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_DerivativeAssets" order="5" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativesFairValueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DerivativeFinancialInstrumentsScheduleofOffsettingofFinancialLiabilitiesandDerivativeLiabilitiesDetailsTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestRateSwapMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_InterestRateSwapMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeLiability" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeCollateralRightToReclaimCash" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeCollateralRightToReclaimCash"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="us-gaap_DerivativeCollateralRightToReclaimCash" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativesFairValueLineItems" xlink:to="us-gaap_DerivativeLiabilities" order="5" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofMajorClassificationofDepositsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_TimeDepositsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDepositsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoninterestBearingDomesticDepositDemand" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestBearingDomesticDepositDemand"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_NoninterestBearingDomesticDepositDemand" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestBearingDomesticDepositDemand" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositDemand"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_InterestBearingDomesticDepositDemand" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsSavingsDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsSavingsDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_DepositsSavingsDeposits" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsMoneyMarketDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsMoneyMarketDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_DepositsMoneyMarketDeposits" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TimeDeposits1" xlink:href="sbfg-20260630.xsd#sbfg_TimeDeposits1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="sbfg_TimeDeposits1" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TimeDeposits2" xlink:href="sbfg-20260630.xsd#sbfg_TimeDeposits2"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="sbfg_TimeDeposits2" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Deposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Deposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_Deposits" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofMajorClassificationofDepositsTable_Parentheticals" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_TimeDepositsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDepositsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TimeDepositsLessThan100000" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDepositsLessThan100000"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_TimeDepositsLessThan100000" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TimeDeposits100000OrMore" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDeposits100000OrMore"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TimeDepositsAbstract" xlink:to="us-gaap_TimeDeposits100000OrMore" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofShortTermBorrowingsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_SecuritySoldShortAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuritySoldShortAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SecuritySoldShortAbstract" xlink:to="us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofAggregateAnnualMaturitiesofFHLBAdvancesTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAbstract" xlink:to="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromTwoToThreeYearsOfBalanceSheetDate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromTwoToThreeYearsOfBalanceSheetDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAbstract" xlink:to="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromTwoToThreeYearsOfBalanceSheetDate" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdvancesFromFederalHomeLoanBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdvancesFromFederalHomeLoanBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAbstract" xlink:to="us-gaap_AdvancesFromFederalHomeLoanBanks" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisDetailsTable" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisDetailsTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofFairValueMeasurementsofAssetsMeasuredatFairValueonaRecurringBasisDetailsTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsRecurringMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain" xlink:to="us-gaap_FairValueMeasurementsRecurringMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USTreasuryAndGovernmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_USTreasuryAndGovernmentMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageBackedSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageBackedSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_MortgageBackedSecuritiesMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_USStatesAndPoliticalSubdivisionsMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_OtherCorporateSecuritiesMember" xlink:href="sbfg-20260630.xsd#sbfg_OtherCorporateSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_OtherCorporateSecuritiesMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_InterestRateContractAssetMember" xlink:href="sbfg-20260630.xsd#sbfg_InterestRateContractAssetMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_InterestRateContractAssetMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_InterestRateContractLiabilitiesMember" xlink:href="sbfg-20260630.xsd#sbfg_InterestRateContractLiabilitiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_InterestRateContractLiabilitiesMember" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ForwardContractsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForwardContractsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_ForwardContractsMember" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestRateLockCommitmentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateLockCommitmentsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_InterestRateLockCommitmentsMember" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueNetAssetLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueNetAssetLiability"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueNetAssetLiability" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofFairValueMeasurementsRecognizedintheAccompanyingCondensedConsolidatedBalanceSheetsUsingSignificantUnobservableTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPeriodIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPeriodIncreaseDecrease"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems" xlink:to="us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPeriodIncreaseDecrease" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofMortgageServicingRightsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofMortgageServicingRightsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofMortgageServicingRightsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:to="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofMortgageServicingRightsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofMortgageServicingRightsDetailsTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofMortgageServicingRightsDetailsTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_IndividuallyEvaluatedLoansMember" xlink:href="sbfg-20260630.xsd#sbfg_IndividuallyEvaluatedLoansMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_IndividuallyEvaluatedLoansMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageBackedSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageBackedSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_MortgageBackedSecuritiesMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LoansReceivableFairValueDisclosure" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansReceivableFairValueDisclosure"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:to="us-gaap_LoansReceivableFairValueDisclosure" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsDetailsTable" xlink:to="srt_RangeAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember_0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsDetailsTable" xlink:to="us-gaap_MeasurementInputTypeAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_MeasurementInputTypeAxis" xlink:to="us-gaap_MeasurementInputTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_DisclosuresAboutFairValueofAssetsandLiabilitiesScheduleofUnobservableInputsUsedinRecurringandNonrecurringLevel3FairValueMeasurementsDetailsTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="12" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputDiscountRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputDiscountRateMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputConstantPrepaymentRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputConstantPrepaymentRateMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputConstantPrepaymentRateMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_PAndIEarningsCreditMember" xlink:href="sbfg-20260630.xsd#sbfg_PAndIEarningsCreditMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="sbfg_PAndIEarningsCreditMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TAndIEarningsCreditMember" xlink:href="sbfg-20260630.xsd#sbfg_TAndIEarningsCreditMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="sbfg_TAndIEarningsCreditMember" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MeasurementInputPriceVolatilityMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_MeasurementInputTypeDomain" xlink:to="us-gaap_MeasurementInputPriceVolatilityMember" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_MortgageServicingRightsMember" xlink:href="sbfg-20260630.xsd#sbfg_MortgageServicingRightsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_MortgageServicingRightsMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_IRLCsMember" xlink:href="sbfg-20260630.xsd#sbfg_IRLCsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_IRLCsMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CollateralDependentImpairedLoansMember" xlink:href="sbfg-20260630.xsd#sbfg_CollateralDependentImpairedLoansMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="sbfg_CollateralDependentImpairedLoansMember" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_FairValueMeasurementValuationTechniques" xlink:href="sbfg-20260630.xsd#sbfg_FairValueMeasurementValuationTechniques"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="sbfg_FairValueMeasurementValuationTechniques" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsSensitivityAnalysisDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsSensitivityAnalysisDescription"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueMeasurementsSensitivityAnalysisDescription" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_RangeWeightedAverage" xlink:href="sbfg-20260630.xsd#sbfg_RangeWeightedAverage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="sbfg_RangeWeightedAverage" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofEstimatedFairValuesoftheCompanysOtherFinancialInstrumentsTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel12And3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel12And3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel12And3Member" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndDueFromBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndDueFromBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_CashAndDueFromBanks" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestBearingDepositsInBanks" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositsInBanks"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_InterestBearingDepositsInBanks" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_AssetsHeldForSaleNotPartOfDisposalGroup" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsReceivableNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_AccountsReceivableNet" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestReceivable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_InterestReceivable" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Deposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Deposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_Deposits" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermBorrowings" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowings"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_ShortTermBorrowings" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesLongTerm" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesLongTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_FederalHomeLoanBankAdvancesLongTerm" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLongTermDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_OtherLongTermDebt" order="9" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubordinatedDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubordinatedDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_SubordinatedDebt" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPayableCurrentAndNoncurrent"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancialInstrumentsOwnedAndPledgedAsCollateralLineItems" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent" order="11" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ScheduleofSummaryofRestrictedStockActivityTable" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_ShareBasedCompensationScheduleofSummaryofRestrictedStockActivityDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_ShareBasedCompensationScheduleofSummaryofRestrictedStockActivityDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="sbfg_ShareBasedCompensationScheduleofSummaryofRestrictedStockActivityDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_ShareBasedCompensationScheduleofSummaryofRestrictedStockActivityDetailsTable" xlink:to="us-gaap_AwardTypeAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RestrictedStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/BusinessCombinationsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="sbfg_BusinessCombinationsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_BusinessCombinationsDetailsTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_BusinessCombinationsDetailsTable" xlink:to="us-gaap_AssetAcquisitionAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetAcquisitionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AssetAcquisitionAxis" xlink:to="us-gaap_AssetAcquisitionDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetAcquisitionDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AssetAcquisitionAxis" xlink:to="us-gaap_AssetAcquisitionDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_MarbleheadMember" xlink:href="sbfg-20260630.xsd#sbfg_MarbleheadMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetAcquisitionDomain" xlink:to="sbfg_MarbleheadMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_BusinessCombinationMember" xlink:href="sbfg-20260630.xsd#sbfg_BusinessCombinationMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="sbfg_BusinessCombinationMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_FixedConsiderationOfCashForEachShares" xlink:href="sbfg-20260630.xsd#sbfg_FixedConsiderationOfCashForEachShares"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="sbfg_FixedConsiderationOfCashForEachShares" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetAcquisitionConsiderationTransferred" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="us-gaap_AssetAcquisitionConsiderationTransferred" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="us-gaap_BusinessCombinationAcquisitionRelatedCosts" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoncashMergerRelatedCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncashMergerRelatedCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="us-gaap_NoncashMergerRelatedCosts" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/AvailableforSaleSecuritiesDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SecuritiesHeldAsCollateralAtFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuritiesHeldAsCollateralAtFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_SecuritiesHeldAsCollateralAtFairValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SecuritiesForReverseRepurchaseAgreements" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuritiesForReverseRepurchaseAgreements"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_SecuritiesForReverseRepurchaseAgreements" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentsFairValueDisclosure" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_InvestmentsFairValueDisclosure" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_NumberOfSecurities" xlink:href="sbfg-20260630.xsd#sbfg_NumberOfSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="sbfg_NumberOfSecurities" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_AvailableForSaleSecuritiesInvestmentPercentage" xlink:href="sbfg-20260630.xsd#sbfg_AvailableForSaleSecuritiesInvestmentPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="sbfg_AvailableForSaleSecuritiesInvestmentPercentage" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossWriteoff" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AvailableForSaleSecuritiesAbstract" xlink:to="us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss" order="7" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/LoansandAllowanceforCreditLossesDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_LoansandAllowanceforCreditLossesDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_LoansandAllowanceforCreditLossesDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:to="sbfg_LoansandAllowanceforCreditLossesDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_LoansandAllowanceforCreditLossesDetailsTable" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis" xlink:to="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_LoansandAllowanceforCreditLossesDetailsTable" xlink:to="us-gaap_DebtInstrumentAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_DebtLoanMember" xlink:href="sbfg-20260630.xsd#sbfg_DebtLoanMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="sbfg_DebtLoanMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnfundedLoanCommitmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnfundedLoanCommitmentMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain" xlink:to="us-gaap_UnfundedLoanCommitmentMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredDiscountsFinanceChargesAndInterestIncludedInReceivables" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredDiscountsFinanceChargesAndInterestIncludedInReceivables"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:to="us-gaap_DeferredDiscountsFinanceChargesAndInterestIncludedInReceivables" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentIncreaseAccruedInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentIncreaseAccruedInterest"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:to="us-gaap_DebtInstrumentIncreaseAccruedInterest" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForOtherCreditLosses" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForOtherCreditLosses"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:to="us-gaap_ProvisionForOtherCreditLosses" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LoansPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansPayable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:to="us-gaap_LoansPayable" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConstructionLoan" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConstructionLoan"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems" xlink:to="us-gaap_ConstructionLoan" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/GoodwillDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_GoodwillDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_GoodwillDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_GoodwillLineItems" xlink:to="sbfg_GoodwillDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_GoodwillDetailsTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_MarbleheadMember" xlink:href="sbfg-20260630.xsd#sbfg_MarbleheadMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="sbfg_MarbleheadMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Goodwill" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_GoodwillLineItems" xlink:to="us-gaap_Goodwill" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_GoodwillLineItems" xlink:to="us-gaap_GoodwillAcquiredDuringPeriod" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillImpairmentLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_GoodwillLineItems" xlink:to="us-gaap_GoodwillImpairmentLoss" order="2" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/MortgageServicingRightsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ParticipatingMortgageLoansLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ParticipatingMortgageLoansLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_MortgageServicingRightsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_MortgageServicingRightsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ParticipatingMortgageLoansLineItems" xlink:to="sbfg_MortgageServicingRightsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnderlyingAssetClassAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnderlyingAssetClassAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_MortgageServicingRightsDetailsTable" xlink:to="us-gaap_UnderlyingAssetClassAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnderlyingAssetClassDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnderlyingAssetClassDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_UnderlyingAssetClassAxis" xlink:to="us-gaap_UnderlyingAssetClassDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnderlyingAssetClassDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnderlyingAssetClassDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_UnderlyingAssetClassAxis" xlink:to="us-gaap_UnderlyingAssetClassDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MortgageBackedSecuritiesOtherMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MortgageBackedSecuritiesOtherMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_UnderlyingAssetClassDomain" xlink:to="us-gaap_MortgageBackedSecuritiesOtherMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_UnpaidPrincipalBalanceOfMortgageLoansServicedForOthers" xlink:href="sbfg-20260630.xsd#sbfg_UnpaidPrincipalBalanceOfMortgageLoansServicedForOthers"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ParticipatingMortgageLoansLineItems" xlink:to="sbfg_UnpaidPrincipalBalanceOfMortgageLoansServicedForOthers" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_ContractuallySpecifiedServicingFees" xlink:href="sbfg-20260630.xsd#sbfg_ContractuallySpecifiedServicingFees"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ParticipatingMortgageLoansLineItems" xlink:to="sbfg_ContractuallySpecifiedServicingFees" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/DepositsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_DepositsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsAbstract"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestBearingDomesticDepositCertificatesOfDeposits" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositCertificatesOfDeposits"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DepositsAbstract" xlink:to="us-gaap_InterestBearingDomesticDepositCertificatesOfDeposits" order="0" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShortTermBorrowingsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_ShortTermBorrowingsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_ShortTermBorrowingsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShortTermDebtLineItems" xlink:to="sbfg_ShortTermBorrowingsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TypeOfArrangementAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfArrangementAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_ShortTermBorrowingsDetailsTable" xlink:to="us-gaap_TypeOfArrangementAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_ShortTermBorrowingsDetailsTable" xlink:to="us-gaap_ShortTermDebtTypeAxis" order="11" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ShortTermDebtTypeAxis" xlink:to="us-gaap_ShortTermDebtTypeDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ShortTermDebtTypeAxis" xlink:to="us-gaap_ShortTermDebtTypeDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_RetailRepurchaseAgreementsMember" xlink:href="sbfg-20260630.xsd#sbfg_RetailRepurchaseAgreementsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="sbfg_RetailRepurchaseAgreementsMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BorrowingsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BorrowingsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtTypeDomain" xlink:to="us-gaap_BorrowingsMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShorttermDebtFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShorttermDebtFairValue"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems" xlink:to="us-gaap_ShorttermDebtFairValue" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems" xlink:to="us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShorttermDebtAverageOutstandingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShorttermDebtAverageOutstandingAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems" xlink:to="us-gaap_ShorttermDebtAverageOutstandingAmount" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentTerm" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTerm"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems" xlink:to="us-gaap_DebtInstrumentTerm" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermBorrowings" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowings"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShortTermDebtLineItems" xlink:to="us-gaap_ShortTermBorrowings" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/FederalHomeLoanBankFHLBAdvancesDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_FederalHomeLoanBankFHLBAdvancesDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_FederalHomeLoanBankFHLBAdvancesDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FederalHomeLoanBankAdvancesLineItems" xlink:to="sbfg_FederalHomeLoanBankFHLBAdvancesDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_FederalHomeLoanBankFHLBAdvancesDetailsTable" xlink:to="srt_RangeAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember_0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SecuredDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebt"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBankAdvancesLineItems" xlink:to="us-gaap_SecuredDebt" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankInterestRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FederalHomeLoanBankAdvancesLineItems" xlink:to="us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankInterestRate" order="1" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/TrustPreferredSecuritiesDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="sbfg_TrustPreferredSecuritiesLineItems" xlink:href="sbfg-20260630.xsd#sbfg_TrustPreferredSecuritiesLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_TrustPreferredSecuritiesDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_TrustPreferredSecuritiesDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="sbfg_TrustPreferredSecuritiesLineItems" xlink:to="sbfg_TrustPreferredSecuritiesDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_TrustPreferredSecuritiesDetailsTable" xlink:to="us-gaap_DebtInstrumentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_CapitalSecuritiesMember" xlink:href="sbfg-20260630.xsd#sbfg_CapitalSecuritiesMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="sbfg_CapitalSecuritiesMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_TrustPreferredSecuritiesLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Cash" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Cash"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_TrustPreferredSecuritiesLineItems" xlink:to="us-gaap_Cash" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DerivativeVariableInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeVariableInterestRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_TrustPreferredSecuritiesLineItems" xlink:to="us-gaap_DerivativeVariableInterestRate" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseCapitalSecurities" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseCapitalSecurities"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_TrustPreferredSecuritiesLineItems" xlink:to="us-gaap_InterestExpenseCapitalSecurities" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="sbfg_TrustPreferredSecuritiesLineItems" xlink:to="us-gaap_DebtInstrumentMaturityDate" order="4" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/SubordinatedDebtDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_SubordinatedBorrowingLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubordinatedBorrowingLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_SubordinatedDebtDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_SubordinatedDebtDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="sbfg_SubordinatedDebtDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_SubordinatedDebtDetailsTable" xlink:to="us-gaap_DebtInstrumentAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_SubordinatedNotePurchaseAgreementsMember" xlink:href="sbfg-20260630.xsd#sbfg_SubordinatedNotePurchaseAgreementsMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="sbfg_SubordinatedNotePurchaseAgreementsMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubordinatedBorrowingInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubordinatedBorrowingInterestRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="us-gaap_SubordinatedBorrowingInterestRate" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="us-gaap_DebtInstrumentMaturityDate" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtPercentageBearingFixedInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtPercentageBearingFixedInterestRate"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="us-gaap_ShortTermDebtPercentageBearingFixedInterestRate" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_RedemptionPriceOutstandingPrincipalAmountPercentage" xlink:href="sbfg-20260630.xsd#sbfg_RedemptionPriceOutstandingPrincipalAmountPercentage"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="sbfg_RedemptionPriceOutstandingPrincipalAmountPercentage" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubordinatedBorrowingLineItems" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts" order="6" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/ShareBasedCompensationDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_ShareBasedCompensationDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_ShareBasedCompensationDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="sbfg_ShareBasedCompensationDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="sbfg_ShareBasedCompensationDetailsTable" xlink:to="us-gaap_PlanNameAxis" order="10" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PlanNameDomain_0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain_0" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="sbfg_TwoThousandSeventeenStockIncentivePlanMember" xlink:href="sbfg-20260630.xsd#sbfg_TwoThousandSeventeenStockIncentivePlanMember"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PlanNameDomain" xlink:to="sbfg_TwoThousandSeventeenStockIncentivePlanMember" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" order="3" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" order="4" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" order="5" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" order="6" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" order="7" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" order="8" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" order="9" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://www.yoursbfinancial.com/role/OperatingSegmentsDetails" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingInformationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <loc xlink:type="locator" xlink:label="sbfg_OperatingSegmentsDetailsTable" xlink:href="sbfg-20260630.xsd#sbfg_OperatingSegmentsDetailsTable"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="sbfg_OperatingSegmentsDetailsTable" order="0" xbrldt:contextElement="segment" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription" order="0" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration" order="1" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NumberOfOperatingSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfOperatingSegments"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_NumberOfOperatingSegments" order="2" xbrldt:closed="true"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NumberOfReportableSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_NumberOfReportableSegments" order="3" xbrldt:closed="true"/>
  </definitionLink>
  <definitionLink xlink:role="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <loc xlink:type="locator" xlink:label="srt_ChiefExecutiveOfficerMember" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ChiefExecutiveOfficerMember"/>
<!-- [WMV7][QddMYWhiNC5n4pJeCxBu/UEK8+jYv5UhCiqKElr6xtznauAZsgHHoS+kiwtcyWCk57Ilhpryv2N0poF2kK8ssI8Dy24CB8hMNmsc9ptC9a12+g/LmhCKT+XI6iNk2St29ZrKUgCrAC8qBtWLSS7a5QPN2lSuECfuKvu14iEGzs3bxPPNmEKg1vOgDeFNt1iIbH1gX9BnZS8y/sxP/o+5UEiry1ZEilwcMx4DdsReF+JtvrX9ioEh6xX8PVknX+uN3qnskfy8koxa5HfRLxbZkT7x7LzpRLyAN1TdgoQb+BgF5SjWdOdUwuo1SvgYwPdICUVHnpjR8Twr0qO/SECdmAMDodthpUg4v9NhNtMu] CSR-->
    <definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="srt_ChiefExecutiveOfficerMember" order="0" xbrldt:closed="true"/>
  </definitionLink>
</linkbase>
