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  <xs:element id="sbsi_FinancingReceivableModifiedNumberOfLoans" abstract="false" name="FinancingReceivableModifiedNumberOfLoans" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="sbsi_FinancingReceivableModifiedSubsequentDefaultNumberOfContracts" abstract="false" name="FinancingReceivableModifiedSubsequentDefaultNumberOfContracts" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="sbsi_CommercialRealEstateOwnerOccupiedRealEstate" abstract="false" name="CommercialRealEstateOwnerOccupiedRealEstate" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_CommercialRealEstateNonOwnerOccupiedRealEstate" abstract="false" name="CommercialRealEstateNonOwnerOccupiedRealEstate" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_DebtTable" abstract="true" name="DebtTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="sbsi_BorrowingsAverageAmountOutstanding" abstract="false" name="BorrowingsAverageAmountOutstanding" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowingsMaximumMonthendOutstandingAmount" abstract="false" name="BorrowingsMaximumMonthendOutstandingAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipalInTheNextRollingTwelveMonths" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipalInTheNextRollingTwelveMonths" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearTwo" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearTwo" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearThree" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearThree" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearFour" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearFive" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingAfterYearFive" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipalInRollingAfterYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_BorrowedFundsMaturitiesRepaymentsOfPrincipal" abstract="false" name="BorrowedFundsMaturitiesRepaymentsOfPrincipal" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_FederalReserveDiscountWindowMember" abstract="true" name="FederalReserveDiscountWindowMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_FrostBankMember" abstract="true" name="FrostBankMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_TibIndependentBankersBankMember" abstract="true" name="TibIndependentBankersBankMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_AmegyBankMember" abstract="true" name="AmegyBankMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_FHLBMember" abstract="true" name="FHLBMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_LineOfCreditFacilityNumberOfCreditLinesMaintainedByCompany" abstract="false" name="LineOfCreditFacilityNumberOfCreditLinesMaintainedByCompany" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="sbsi_RepurchaseAgreementCounterpartyMaturityofAgreements" abstract="false" name="RepurchaseAgreementCounterpartyMaturityofAgreements" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="sbsi_FederalHomeLoanBankAdvancesMaturitiesSummaryMaturityRange" abstract="false" name="FederalHomeLoanBankAdvancesMaturitiesSummaryMaturityRange" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="sbsi_Numberofoutstandinglettersofcredit" abstract="false" name="Numberofoutstandinglettersofcredit" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="sbsi_A3875SubordinatedNotesMember" abstract="true" name="A3875SubordinatedNotesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_A7.0SubordinatedNotesDue2035Member" abstract="true" name="A7.0SubordinatedNotesDue2035Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_SouthsideStatutoryTrustIIInetofunamortizeddebtissuancecostsMember" abstract="true" name="SouthsideStatutoryTrustIIInetofunamortizeddebtissuancecostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_SouthsideStatutoryTrustIvMember" abstract="true" name="SouthsideStatutoryTrustIvMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_SouthsideStatutoryTrustVMember" abstract="true" name="SouthsideStatutoryTrustVMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_MagnoliaTrustCompanyIMember" abstract="true" name="MagnoliaTrustCompanyIMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_SubordinatedNotesRemainingMaturity" abstract="false" name="SubordinatedNotesRemainingMaturity" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="sbsi_AcceleratedAmortizationOfDebtIssuanceCostsAndDiscounts" abstract="false" name="AcceleratedAmortizationOfDebtIssuanceCostsAndDiscounts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_NoncashAdjustmentToPensionLiability" abstract="false" name="NoncashAdjustmentToPensionLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_FinancialInstitutionCounterpartiesMember" abstract="true" name="FinancialInstitutionCounterpartiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_CustomerCounterpartiesMember" abstract="true" name="CustomerCounterpartiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sbsi_DerivativeWeightedAverageReceiveRate" abstract="false" name="DerivativeWeightedAverageReceiveRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="sbsi_DerivativeWeightedAveragePayRate" abstract="false" name="DerivativeWeightedAveragePayRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="sbsi_NumberofThirdPartySourcesUsedtoValidatePrices" abstract="false" name="NumberofThirdPartySourcesUsedtoValidatePrices" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="sbsi_InvestmentSecuritiesHeldtomaturitySecuritiesFairValueDisclosure" abstract="false" name="InvestmentSecuritiesHeldtomaturitySecuritiesFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_MortgageBackedAndRelatedSecuritiesAbstract" abstract="true" name="MortgageBackedAndRelatedSecuritiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="sbsi_UnsettledTradesToSellSecurities" abstract="false" name="UnsettledTradesToSellSecurities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sbsi_UnsettledIssuancesofBrokeredCDs" abstract="false" name="UnsettledIssuancesofBrokeredCDs" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
