<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2022 Workiva-->
<!--r:2eb8417c-8f18-4639-9e9b-0fdc4f9ff19a,g:a389b4e3-4989-454d-b3d5-32370c2f27cb-->
<link:linkbase xmlns:link="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">
  <link:roleRef roleURI="http://www.southside.com/role/CONSOLIDATEDBALANCESHEETSUNAUDITED" xlink:type="simple" xlink:href="sbsi-20220331.xsd#CONSOLIDATEDBALANCESHEETSUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/CONSOLIDATEDBALANCESHEETSUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_b09df3b8-5ce8-476e-a1a1-dbe7acaf7740" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Deposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilities_cdb6177c-e1dc-4ec5-8f98-128fd2c346b3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestBearingDepositLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_b09df3b8-5ce8-476e-a1a1-dbe7acaf7740" xlink:to="loc_us-gaap_InterestBearingDepositLiabilities_cdb6177c-e1dc-4ec5-8f98-128fd2c346b3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilities_b1537ce6-d9e8-4dc0-8749-ab61387b36ec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_b09df3b8-5ce8-476e-a1a1-dbe7acaf7740" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilities_b1537ce6-d9e8-4dc0-8749-ab61387b36ec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_ff935d5d-3ffd-46ea-b61c-3161612c84f4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositsInBanks_38910a8a-e265-4b1a-bfea-53618d96a9af" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestBearingDepositsInBanks"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_ff935d5d-3ffd-46ea-b61c-3161612c84f4" xlink:to="loc_us-gaap_InterestBearingDepositsInBanks_38910a8a-e265-4b1a-bfea-53618d96a9af" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndDueFromBanks_bc55b767-8664-46ca-a6c0-3eb036844b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndDueFromBanks"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_ff935d5d-3ffd-46ea-b61c-3161612c84f4" xlink:to="loc_us-gaap_CashAndDueFromBanks_bc55b767-8664-46ca-a6c0-3eb036844b1e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsSold_c67417fd-da31-4f53-8ed5-dde89ffa1846" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalFundsSold"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_ff935d5d-3ffd-46ea-b61c-3161612c84f4" xlink:to="loc_us-gaap_FederalFundsSold_c67417fd-da31-4f53-8ed5-dde89ffa1846" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_7515fa1f-9d2e-41ad-b106-86da6d4f2b96" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_ba55557a-f51e-4620-992d-42153cd67ad3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_7515fa1f-9d2e-41ad-b106-86da6d4f2b96" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_ba55557a-f51e-4620-992d-42153cd67ad3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_c4080eb6-1eb0-48d2-9a2b-c3a900f5a304" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_7515fa1f-9d2e-41ad-b106-86da6d4f2b96" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_c4080eb6-1eb0-48d2-9a2b-c3a900f5a304" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_ce9bb925-dfbd-4dfb-8d82-73cab567c1ed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_14a44528-3991-4550-9a7c-fb749d8d62ce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_ce9bb925-dfbd-4dfb-8d82-73cab567c1ed" xlink:to="loc_us-gaap_CommonStockValue_14a44528-3991-4550-9a7c-fb749d8d62ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_159e0578-c0a1-4e30-89ba-d863957a373f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_ce9bb925-dfbd-4dfb-8d82-73cab567c1ed" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_159e0578-c0a1-4e30-89ba-d863957a373f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_063b25e7-a22d-4ab5-b0f5-b3be25ec8050" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_ce9bb925-dfbd-4dfb-8d82-73cab567c1ed" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_063b25e7-a22d-4ab5-b0f5-b3be25ec8050" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValue_e7310909-9061-4961-84a6-1138790028ff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockValue"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_ce9bb925-dfbd-4dfb-8d82-73cab567c1ed" xlink:to="loc_us-gaap_TreasuryStockValue_e7310909-9061-4961-84a6-1138790028ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_22559fb4-68b6-4848-a395-cdc2f21c84ab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_ce9bb925-dfbd-4dfb-8d82-73cab567c1ed" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_22559fb4-68b6-4848-a395-cdc2f21c84ab" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_d6277a51-d63f-443e-b3b6-930f31d6e02a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_7a58ba28-b6d6-4f1f-ae35-76ea74e5f436" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_d6277a51-d63f-443e-b3b6-930f31d6e02a" xlink:to="loc_us-gaap_Liabilities_7a58ba28-b6d6-4f1f-ae35-76ea74e5f436" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_796193ad-76e1-4bc2-bcae-c34859311579" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_d6277a51-d63f-443e-b3b6-930f31d6e02a" xlink:to="loc_us-gaap_StockholdersEquity_796193ad-76e1-4bc2-bcae-c34859311579" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_52a2bf26-c1eb-4c2a-93d7-5a4d8ae05fd7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_d6277a51-d63f-443e-b3b6-930f31d6e02a" xlink:to="loc_us-gaap_CommitmentsAndContingencies_52a2bf26-c1eb-4c2a-93d7-5a4d8ae05fd7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_d88e971d-0ca9-4e24-8d00-3426e64cf277" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_d88e971d-0ca9-4e24-8d00-3426e64cf277" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_UnsettledTradesToSellSecurities_53b4d7eb-d78a-42ee-986b-4de5a465be74" xlink:href="sbsi-20220331.xsd#sbsi_UnsettledTradesToSellSecurities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_sbsi_UnsettledTradesToSellSecurities_53b4d7eb-d78a-42ee-986b-4de5a465be74" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue_28d831e0-1457-4cc4-89e3-11aa576ddae4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_EquitySecuritiesFvNiAndWithoutReadilyDeterminableFairValue_28d831e0-1457-4cc4-89e3-11aa576ddae4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsurance_b57a9d69-19f2-4f13-8950-0fe0415efe39" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BankOwnedLifeInsurance"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_BankOwnedLifeInsurance_b57a9d69-19f2-4f13-8950-0fe0415efe39" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_0be9f1ff-59f5-45a7-b6c1-b0e3df3e3ace" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_0be9f1ff-59f5-45a7-b6c1-b0e3df3e3ace" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankStock_1abc506c-c76f-419f-a2f3-b7a8f29790a5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalHomeLoanBankStock"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_FederalHomeLoanBankStock_1abc506c-c76f-419f-a2f3-b7a8f29790a5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_da241f51-dbc7-4867-b6d6-f876ecb901a5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_da241f51-dbc7-4867-b6d6-f876ecb901a5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_94438272-2162-4293-aced-7ee0b217c14e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_94438272-2162-4293-aced-7ee0b217c14e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_c47eebea-c8a6-4234-aa53-63fb96408a8f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_c47eebea-c8a6-4234-aa53-63fb96408a8f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_b1869fa8-97fe-4dfe-9940-3b470ffc44f6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_b1869fa8-97fe-4dfe-9940-3b470ffc44f6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_b7e3489c-34d5-4e84-afd3-4957e108b585" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_b7e3489c-34d5-4e84-afd3-4957e108b585" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestReceivable_c0f90bdd-7b9f-4584-bad4-b696e0c82c97" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestReceivable"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_InterestReceivable_c0f90bdd-7b9f-4584-bad4-b696e0c82c97" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_12e74c14-8a24-4de2-bd09-a51acc957ec3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_Goodwill_12e74c14-8a24-4de2-bd09-a51acc957ec3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss_7df07688-dbda-467c-a87d-7a5fefbb7c66" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss_7df07688-dbda-467c-a87d-7a5fefbb7c66" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_67d4d6f7-4265-4dc1-a633-d4b0b326b926" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssets"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_OtherAssets_67d4d6f7-4265-4dc1-a633-d4b0b326b926" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup_500b9048-3644-4c06-9e37-2e9a138a888b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup"/>
    <link:calculationArc order="16" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_c6b74dd4-2313-45bf-b8e6-35e7ea762145" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup_500b9048-3644-4c06-9e37-2e9a138a888b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_2bb2f0a6-88ba-40d7-b1c3-6c11c14e4f6a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Deposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_Deposits_2bb2f0a6-88ba-40d7-b1c3-6c11c14e4f6a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase_2ce02ea1-5ddb-4527-b123-a8ca666460ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase_2ce02ea1-5ddb-4527-b123-a8ca666460ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch_490a4a2e-aacc-458f-9453-e3d5f0b5d7b8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankAmountOfAdvancesByBranch_490a4a2e-aacc-458f-9453-e3d5f0b5d7b8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebt_a94fa6af-5293-46b1-b743-d480b8225f49" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubordinatedDebt"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_SubordinatedDebt_a94fa6af-5293-46b1-b743-d480b8225f49" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_c786524a-657f-4814-b587-e9a403446511" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_c786524a-657f-4814-b587-e9a403446511" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_UnsettledTradesToPurchaseSecuritiesLiability_1ad36251-8814-4ddc-9f19-3c39c369481f" xlink:href="sbsi-20220331.xsd#sbsi_UnsettledTradesToPurchaseSecuritiesLiability"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_sbsi_UnsettledTradesToPurchaseSecuritiesLiability_1ad36251-8814-4ddc-9f19-3c39c369481f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_de47d2ab-2048-47eb-a7c9-e8848c8d6727" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_OtherLiabilities_de47d2ab-2048-47eb-a7c9-e8848c8d6727" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_513d73c5-1b45-4ebf-9bf2-40b0b8237f03" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_OperatingLeaseLiability_513d73c5-1b45-4ebf-9bf2-40b0b8237f03" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_6c9d29a2-49c3-4766-883c-5fa8d7fc9fa3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_5adb47f6-b1cf-4c1a-afa7-93e2f45d7370" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_6c9d29a2-49c3-4766-883c-5fa8d7fc9fa3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/CONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED" xlink:type="simple" xlink:href="sbsi-20220331.xsd#CONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/CONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_def7ebda-7e52-4477-89e3-5664513b5cda" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_def7ebda-7e52-4477-89e3-5664513b5cda" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketingAndAdvertisingExpense_735527d5-63c6-4435-8527-0675a78eecea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MarketingAndAdvertisingExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_MarketingAndAdvertisingExpense_735527d5-63c6-4435-8527-0675a78eecea" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_a340b396-7d45-4025-82eb-03cdc1e92967" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_LaborAndRelatedExpense_a340b396-7d45-4025-82eb-03cdc1e92967" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_74ecfe85-feb1-42bb-aa9c-98dfb0924e0e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_74ecfe85-feb1-42bb-aa9c-98dfb0924e0e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_c1d37c82-f7cd-48f4-b1ce-0dee8d5293a3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_ProfessionalFees_c1d37c82-f7cd-48f4-b1ce-0dee8d5293a3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_e6a6d3d7-97ec-46fe-84a1-7faf2e5434d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_e6a6d3d7-97ec-46fe-84a1-7faf2e5434d6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Communication_a0337603-8913-41fd-aabd-ab9ecdc2dad7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Communication"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_Communication_a0337603-8913-41fd-aabd-ab9ecdc2dad7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_96d25162-b307-43ff-9d78-8acd3b986255" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OccupancyNet"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_OccupancyNet_96d25162-b307-43ff-9d78-8acd3b986255" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_ATMExpense_64079d2a-82e7-4522-bcfa-023c91246fe0" xlink:href="sbsi-20220331.xsd#sbsi_ATMExpense"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_sbsi_ATMExpense_64079d2a-82e7-4522-bcfa-023c91246fe0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_a8fc9ab9-bd35-4f03-80a9-e4d654a186c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_OtherNoninterestExpense_a8fc9ab9-bd35-4f03-80a9-e4d654a186c1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_cdf72ca0-39e1-4a37-92cb-0738e8a827e6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FederalDepositInsuranceCorporationPremiumExpense"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_19a9d756-6f66-4b9b-9732-a0cbffa8b0ae" xlink:to="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_cdf72ca0-39e1-4a37-92cb-0738e8a827e6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_1bfe9d6b-087e-497f-9406-32b7a6c23d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_3019bc95-95a4-416a-98f7-d8fc199cd37d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_1bfe9d6b-087e-497f-9406-32b7a6c23d6a" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_3019bc95-95a4-416a-98f7-d8fc199cd37d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_a0082000-fa4c-473a-82c0-b892b6a07b57" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_1bfe9d6b-087e-497f-9406-32b7a6c23d6a" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_a0082000-fa4c-473a-82c0-b892b6a07b57" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_67742977-adc6-4a7d-b5a6-69fecb70592d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDeposits_a2eea37c-7f9d-49cf-809b-0f624088aed3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_67742977-adc6-4a7d-b5a6-69fecb70592d" xlink:to="loc_us-gaap_InterestExpenseDeposits_a2eea37c-7f9d-49cf-809b-0f624088aed3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm_c791eb23-f5be-40f8-a5b5-5a8c757e82d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_67742977-adc6-4a7d-b5a6-69fecb70592d" xlink:to="loc_us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm_c791eb23-f5be-40f8-a5b5-5a8c757e82d6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseSubordinatedNotesAndDebentures_6d6e0328-9246-47f1-b167-cf93e31b03d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseSubordinatedNotesAndDebentures"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_67742977-adc6-4a7d-b5a6-69fecb70592d" xlink:to="loc_us-gaap_InterestExpenseSubordinatedNotesAndDebentures_6d6e0328-9246-47f1-b167-cf93e31b03d6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseJuniorSubordinatedDebentures_b8fa8b90-e300-4fc3-a9c7-0956a3f20f57" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseJuniorSubordinatedDebentures"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_67742977-adc6-4a7d-b5a6-69fecb70592d" xlink:to="loc_us-gaap_InterestExpenseJuniorSubordinatedDebentures_b8fa8b90-e300-4fc3-a9c7-0956a3f20f57" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOther_2399e068-a4df-44a7-9570-f11660a02bb0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseOther"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_67742977-adc6-4a7d-b5a6-69fecb70592d" xlink:to="loc_us-gaap_InterestExpenseOther_2399e068-a4df-44a7-9570-f11660a02bb0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_4df027ce-abdb-462f-a988-cf78f2319939" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_e428c527-a46f-4dec-88a1-22f526fc028a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_4df027ce-abdb-462f-a988-cf78f2319939" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_e428c527-a46f-4dec-88a1-22f526fc028a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_9e7d0450-88ae-4a4a-adc7-ae6f50632117" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_4df027ce-abdb-462f-a988-cf78f2319939" xlink:to="loc_us-gaap_InterestExpense_9e7d0450-88ae-4a4a-adc7-ae6f50632117" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_ba311f46-a501-43ec-a10b-a8ed20786a17" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_6a005b2f-1480-4b5a-aa85-b01c97d98bf8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_ba311f46-a501-43ec-a10b-a8ed20786a17" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_6a005b2f-1480-4b5a-aa85-b01c97d98bf8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_6e1d1e62-8fdc-4d94-93de-644b18605b8d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_ba311f46-a501-43ec-a10b-a8ed20786a17" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_6e1d1e62-8fdc-4d94-93de-644b18605b8d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_FeeAndCommissionsDepositorAccount_22e31400-af9d-4acd-a1f1-20b3f2f2b36a" xlink:href="sbsi-20220331.xsd#sbsi_FeeAndCommissionsDepositorAccount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_sbsi_FeeAndCommissionsDepositorAccount_22e31400-af9d-4acd-a1f1-20b3f2f2b36a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfLoansNet_d4da3b11-4eab-4be9-8892-cd531bfa5ef1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_us-gaap_GainLossOnSalesOfLoansNet_d4da3b11-4eab-4be9-8892-cd531bfa5ef1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_FeesAndCommissionsFiduciaryAndTrustActivity_25c9dc0a-a0be-49cf-a83f-70ba60912232" xlink:href="sbsi-20220331.xsd#sbsi_FeesAndCommissionsFiduciaryAndTrustActivity"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_sbsi_FeesAndCommissionsFiduciaryAndTrustActivity_25c9dc0a-a0be-49cf-a83f-70ba60912232" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsuranceIncome_018e4ee9-0048-4104-892e-9593927b3cd8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BankOwnedLifeInsuranceIncome"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_us-gaap_BankOwnedLifeInsuranceIncome_018e4ee9-0048-4104-892e-9593927b3cd8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BrokerageCommissionsRevenue_6ebad2fa-b167-4512-bae1-1a1113bb38d9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BrokerageCommissionsRevenue"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_us-gaap_BrokerageCommissionsRevenue_6ebad2fa-b167-4512-bae1-1a1113bb38d9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeOtherOperatingIncome_a419c36b-a535-4c8a-8ee6-ace20c6dd825" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestIncomeOtherOperatingIncome"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_us-gaap_NoninterestIncomeOtherOperatingIncome_a419c36b-a535-4c8a-8ee6-ace20c6dd825" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_786a480e-71a6-452e-947a-22d7456ea639" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_9bf8716f-dc28-489d-b6fb-81537cb9d211" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_786a480e-71a6-452e-947a-22d7456ea639" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_74b21101-de53-46d7-9747-9354e24f6233" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_74b21101-de53-46d7-9747-9354e24f6233" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxable_98e45a81-e24e-4a34-8791-a5f6e3ac52ff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxable"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxable_98e45a81-e24e-4a34-8791-a5f6e3ac52ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_1ab06944-53f7-455c-98dc-63592194de6e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_1ab06944-53f7-455c-98dc-63592194de6e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesMortgageBacked_cc6435b2-a5cb-4d9f-80fd-3029055d30e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesMortgageBacked"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:to="loc_us-gaap_InterestIncomeSecuritiesMortgageBacked_cc6435b2-a5cb-4d9f-80fd-3029055d30e9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInterestAndDividendIncome_cfca0b94-434a-4184-a26f-839d07922a83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherInterestAndDividendIncome"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:to="loc_us-gaap_OtherInterestAndDividendIncome_cfca0b94-434a-4184-a26f-839d07922a83" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOther_4fec38c0-2278-4a41-8972-3049193b5be6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeOther"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_97ef0da7-8d89-4ec6-9fba-1775c866023c" xlink:to="loc_us-gaap_InterestIncomeOther_4fec38c0-2278-4a41-8972-3049193b5be6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_d58c67ce-6c1e-4a40-a492-65dab76cd3ad" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_6ca2564e-56e7-4f8d-8fbe-9eec98ae8782" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_d58c67ce-6c1e-4a40-a492-65dab76cd3ad" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_6ca2564e-56e7-4f8d-8fbe-9eec98ae8782" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_df4c9936-3c59-44f1-8535-8facb8929e1b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestIncome"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_d58c67ce-6c1e-4a40-a492-65dab76cd3ad" xlink:to="loc_us-gaap_NoninterestIncome_df4c9936-3c59-44f1-8535-8facb8929e1b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_f971ee71-e805-432f-99b5-ad841e2ffcbe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoninterestExpense"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_d58c67ce-6c1e-4a40-a492-65dab76cd3ad" xlink:to="loc_us-gaap_NoninterestExpense_f971ee71-e805-432f-99b5-ad841e2ffcbe" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUNAUDITED" xlink:type="simple" xlink:href="sbsi-20220331.xsd#CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_60ff6bbd-5cdb-40b7-b424-606957a48d85" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d0aa363e-6833-4b79-92d5-6de1682cfe44" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_60ff6bbd-5cdb-40b7-b424-606957a48d85" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d0aa363e-6833-4b79-92d5-6de1682cfe44" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_621c0614-0fcc-4c5e-8025-08fa61fc4492" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_60ff6bbd-5cdb-40b7-b424-606957a48d85" xlink:to="loc_us-gaap_NetIncomeLoss_621c0614-0fcc-4c5e-8025-08fa61fc4492" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_OCIDebtSecuritiesAvailableForSaleTransferToHeldToMaturityGainLossBeforeAdjustmentAndTax_0fef9639-57c6-4db0-be4e-b3b6ebc06b74" xlink:href="sbsi-20220331.xsd#sbsi_OCIDebtSecuritiesAvailableForSaleTransferToHeldToMaturityGainLossBeforeAdjustmentAndTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_sbsi_OCIDebtSecuritiesAvailableForSaleTransferToHeldToMaturityGainLossBeforeAdjustmentAndTax_0fef9639-57c6-4db0-be4e-b3b6ebc06b74" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax_a100c1bf-0c18-43c6-b71a-18da17348a1a" xlink:href="sbsi-20220331.xsd#sbsi_OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_sbsi_OtherComprehensiveIncomeLossDefinedBenefitPlanGainLossandPriorServiceCostCreditReclassificationAdjustmentfromAOCIbeforeTax_a100c1bf-0c18-43c6-b71a-18da17348a1a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_96a36a5c-f7a7-4e8b-b964-701d7578a034" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_96a36a5c-f7a7-4e8b-b964-701d7578a034" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax_c5224c47-04c8-4b92-8a5e-ac16ffa06855" xlink:href="sbsi-20220331.xsd#sbsi_AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_sbsi_AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax_c5224c47-04c8-4b92-8a5e-ac16ffa06855" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_f280a14d-dec0-4252-b63c-358763390aa5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_f280a14d-dec0-4252-b63c-358763390aa5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_59ffbaab-8e59-4235-9409-ebbd05763c8d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_59ffbaab-8e59-4235-9409-ebbd05763c8d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax_b37bfac7-41a9-4015-9256-383c9c922064" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_f8cdf26a-dd69-47c8-8000-356608465332" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsAndTax_b37bfac7-41a9-4015-9256-383c9c922064" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_21331246-b19a-4c13-a6fe-f4d5b735eafb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_c0db7535-2b27-4904-94c1-15cd05bd717f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_21331246-b19a-4c13-a6fe-f4d5b735eafb" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_c0db7535-2b27-4904-94c1-15cd05bd717f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_0f9aabe5-6c03-458c-8419-a8790b126170" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_21331246-b19a-4c13-a6fe-f4d5b735eafb" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_0f9aabe5-6c03-458c-8419-a8790b126170" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="simple" xlink:href="sbsi-20220331.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan_63b5d984-dd61-4b1c-b6ec-b6802f1f8ddc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan_63b5d984-dd61-4b1c-b6ec-b6802f1f8ddc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_886d5fa0-c72b-47e6-bb0e-6978eda107c3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromDebtNetOfIssuanceCosts"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_886d5fa0-c72b-47e6-bb0e-6978eda107c3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings_252e85b9-f72d-48df-be43-756710ac8568" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings_252e85b9-f72d-48df-be43-756710ac8568" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_b40638f4-8179-444d-a8a8-946e51446633" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_b40638f4-8179-444d-a8a8-946e51446633" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSubordinatedDebt_ca8d76a9-bda4-4671-a603-d6a922d3d478" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfSubordinatedDebt"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_RepaymentsOfSubordinatedDebt_ca8d76a9-bda4-4671-a603-d6a922d3d478" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_e554a0a3-73b3-4668-973b-c8d7fd783472" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_e554a0a3-73b3-4668-973b-c8d7fd783472" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_109b24e6-0c75-448d-9782-e4bebb6a22e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_109b24e6-0c75-448d-9782-e4bebb6a22e4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet_e54adcab-f864-4996-9ea7-2415bbe80474" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_IncreaseDecreaseInFederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchaseNet_e54adcab-f864-4996-9ea7-2415bbe80474" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetChangeInterestAndNoninterestBearingDepositsDomestic_9c9a3f46-283c-4c88-beb3-f17a502c5637" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetChangeInterestAndNoninterestBearingDepositsDomestic"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_NetChangeInterestAndNoninterestBearingDepositsDomestic_9c9a3f46-283c-4c88-beb3-f17a502c5637" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_5d009764-f1dd-4fc7-9b82-9fc646496da0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_5d009764-f1dd-4fc7-9b82-9fc646496da0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromFederalHomeLoanBankBorrowings_476be9c1-7472-4786-ad37-9a3f12278db0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromFederalHomeLoanBankBorrowings"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_22aac453-e3b1-476e-b644-0db1a2a7e24c" xlink:to="loc_us-gaap_ProceedsFromFederalHomeLoanBankBorrowings_476be9c1-7472-4786-ad37-9a3f12278db0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_5a0da12c-53ca-4f51-91db-96b195f5f1f4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_5a0da12c-53ca-4f51-91db-96b195f5f1f4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_a089abd1-1e50-4e69-9ce8-dc2a102fde3c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_a089abd1-1e50-4e69-9ce8-dc2a102fde3c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_e5d0742c-34c7-4c23-9dae-cb96436ed87d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_e5d0742c-34c7-4c23-9dae-cb96436ed87d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_2087f562-1343-4a5e-aa7c-a15310c79f4f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_2087f562-1343-4a5e-aa7c-a15310c79f4f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_d1c4905f-5754-4357-9ba8-9a56ca1cc745" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_d1c4905f-5754-4357-9ba8-9a56ca1cc745" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_9418d806-e6a4-4e40-bbd9-146132bc91c2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_9418d806-e6a4-4e40-bbd9-146132bc91c2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_4172a51f-7d58-4aea-b5f6-f68bc680c1e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_4172a51f-7d58-4aea-b5f6-f68bc680c1e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_16afe6b1-f3e2-4cba-a119-4ebc3eea0955" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_16afe6b1-f3e2-4cba-a119-4ebc3eea0955" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_a7c68cf6-f4e5-4f51-b23a-205e6501148d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_a7c68cf6-f4e5-4f51-b23a-205e6501148d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale_1635ab5a-6060-45f4-ae70-3a08494e4115" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale_1635ab5a-6060-45f4-ae70-3a08494e4115" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale_9751c07d-b206-43a5-8305-6f32c254cada" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale_9751c07d-b206-43a5-8305-6f32c254cada" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium_7d3b97da-3d36-43b9-9d73-2ce97dda5201" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_InvestmentIncomeNetAmortizationOfDiscountAndPremium_7d3b97da-3d36-43b9-9d73-2ce97dda5201" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_6df49ee0-1cd5-4620-aff3-05b8119d91cf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_ProfitLoss_6df49ee0-1cd5-4620-aff3-05b8119d91cf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_0eba923b-22d6-41b7-bd4c-f65647c04d76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_ShareBasedCompensation_0eba923b-22d6-41b7-bd4c-f65647c04d76" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_2a81aa0a-af76-4068-abee-911cd2ef81ff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="15" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_2a81aa0a-af76-4068-abee-911cd2ef81ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_AvailableForSaleSecuritiesLossOnImpairment_1529d3f3-8358-44c2-b65a-6be5a3345038" xlink:href="sbsi-20220331.xsd#sbsi_AvailableForSaleSecuritiesLossOnImpairment"/>
    <link:calculationArc order="16" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_sbsi_AvailableForSaleSecuritiesLossOnImpairment_1529d3f3-8358-44c2-b65a-6be5a3345038" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnSalesOfOtherRealEstate_2f36a500-82a0-46a4-8975-37df6a06c819" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnSalesOfOtherRealEstate"/>
    <link:calculationArc order="17" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_GainsLossesOnSalesOfOtherRealEstate_2f36a500-82a0-46a4-8975-37df6a06c819" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_df6f741e-eb64-4d44-aa96-0eaaf05c9eaf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:calculationArc order="18" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_df6f741e-eb64-4d44-aa96-0eaaf05c9eaf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_faf85b07-078e-4683-a67e-60b7b2ea7389" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments"/>
    <link:calculationArc order="19" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_5a603eca-450c-4653-a4bb-bd9e076bb5ac" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_faf85b07-078e-4683-a67e-60b7b2ea7389" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_474f7729-3ff2-46f9-b9a6-6d6d082cb4d6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_2ed6dd74-6f2f-4cc2-9921-4bb89527ab73" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_474f7729-3ff2-46f9-b9a6-6d6d082cb4d6" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_2ed6dd74-6f2f-4cc2-9921-4bb89527ab73" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_0de26f8a-2dbb-40c0-902d-9ee671cc880d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_474f7729-3ff2-46f9-b9a6-6d6d082cb4d6" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_0de26f8a-2dbb-40c0-902d-9ee671cc880d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_66faf174-bc65-4dc4-804e-f218ea24a65f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_474f7729-3ff2-46f9-b9a6-6d6d082cb4d6" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_66faf174-bc65-4dc4-804e-f218ea24a65f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_891f47e5-c10e-4ed7-bfbb-1a0a9f8dec32" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_891f47e5-c10e-4ed7-bfbb-1a0a9f8dec32" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromLoansAndLeases_14c2bd74-3e84-4d76-ba6f-9707ef09160a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForProceedsFromLoansAndLeases"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_PaymentsForProceedsFromLoansAndLeases_14c2bd74-3e84-4d76-ba6f-9707ef09160a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans_71951b27-8b24-417e-839a-803d51dc42bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans_71951b27-8b24-417e-839a-803d51dc42bc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromLifeInsurancePolicies_e191840e-ccb6-4312-9580-a1f5a9ba1867" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsForProceedsFromLifeInsurancePolicies"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_PaymentsForProceedsFromLifeInsurancePolicies_e191840e-ccb6-4312-9580-a1f5a9ba1867" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_e5fd4574-be52-453f-9a26-529f6317ab1f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_e5fd4574-be52-453f-9a26-529f6317ab1f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_a2cd2a0f-a77b-4e81-a131-57e6fe995169" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_a2cd2a0f-a77b-4e81-a131-57e6fe995169" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_7300d41b-d935-4dd2-bd6a-d4d808a29d89" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_7300d41b-d935-4dd2-bd6a-d4d808a29d89" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_0d80f17b-40f1-48c6-85bf-7c2eb935a31e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_0d80f17b-40f1-48c6-85bf-7c2eb935a31e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock_8448551c-73e6-4cc9-9844-1d6ff045cf79" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock_8448551c-73e6-4cc9-9844-1d6ff045cf79" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireFederalHomeLoanBankStock_7059d46d-98d5-4da0-bf67-810ee31913f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireFederalHomeLoanBankStock"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_PaymentsToAcquireFederalHomeLoanBankStock_7059d46d-98d5-4da0-bf67-810ee31913f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities_7730a4c0-41c9-4b84-bff6-860f82f9750e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities_7730a4c0-41c9-4b84-bff6-860f82f9750e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfForeclosedAssets_4eb6447f-3b9b-468f-902b-41059c96e9d2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfForeclosedAssets"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_10e1ec83-58a0-4224-b473-acbd698c9178" xlink:to="loc_us-gaap_ProceedsFromSaleOfForeclosedAssets_4eb6447f-3b9b-468f-902b-41059c96e9d2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/EarningsPerShareDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#EarningsPerShareDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/EarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_39255e4c-3198-4b14-9750-c03028745629" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_d957674b-60eb-4d79-b8fe-20207c5b07a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_39255e4c-3198-4b14-9750-c03028745629" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_d957674b-60eb-4d79-b8fe-20207c5b07a2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_56aabba7-c96f-4025-9ec3-200f4340cf5f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_39255e4c-3198-4b14-9750-c03028745629" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_56aabba7-c96f-4025-9ec3-200f4340cf5f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/AccumulatedOtherComprehensiveIncomeLossAccumulatedOtherComprehensiveIncomeChangesInDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#AccumulatedOtherComprehensiveIncomeLossAccumulatedOtherComprehensiveIncomeChangesInDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/AccumulatedOtherComprehensiveIncomeLossAccumulatedOtherComprehensiveIncomeChangesInDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_de635f55-6c80-47c2-b64f-31698efe4a32" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_a8f5eb0c-5d84-4038-bd78-82185bcca999" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_de635f55-6c80-47c2-b64f-31698efe4a32" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_a8f5eb0c-5d84-4038-bd78-82185bcca999" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_8f49074a-4f18-49e3-b909-5b292243537e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_de635f55-6c80-47c2-b64f-31698efe4a32" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_8f49074a-4f18-49e3-b909-5b292243537e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_45e6cf27-a417-4ac3-8d95-0b5dce15d59e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_de635f55-6c80-47c2-b64f-31698efe4a32" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_45e6cf27-a417-4ac3-8d95-0b5dce15d59e" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/AccumulatedOtherComprehensiveIncomeLossReclassificationsoutofAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#AccumulatedOtherComprehensiveIncomeLossReclassificationsoutofAccumulatedOtherComprehensiveIncomeDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/AccumulatedOtherComprehensiveIncomeLossReclassificationsoutofAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_fd1fc88c-4060-47f5-bb04-971bd4b4f3f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperations"/>
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax_fe2cef4a-ed3d-4f33-b8fe-4c28c458ce5f" xlink:href="sbsi-20220331.xsd#sbsi_AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperations_fd1fc88c-4060-47f5-bb04-971bd4b4f3f0" xlink:to="loc_sbsi_AmortizationofUnrealizedGainsLossesonSecuritiesTransferredBetweenAvailableforSaleAndHeldtoMaturityDebtSecuritiesBeforeTax_fe2cef4a-ed3d-4f33-b8fe-4c28c458ce5f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_ea900dd1-1bc5-4e15-9a75-45613e2005e5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperations_fd1fc88c-4060-47f5-bb04-971bd4b4f3f0" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_ea900dd1-1bc5-4e15-9a75-45613e2005e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_b53d4504-b144-492a-b550-9f1138ab796e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperations_fd1fc88c-4060-47f5-bb04-971bd4b4f3f0" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_b53d4504-b144-492a-b550-9f1138ab796e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_e0993c3e-7111-47b4-9ca9-144d17727376" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperations_fd1fc88c-4060-47f5-bb04-971bd4b4f3f0" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_e0993c3e-7111-47b4-9ca9-144d17727376" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_94a06a2e-8f38-4b6f-b5f7-5910a44c3612" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperations_fd1fc88c-4060-47f5-bb04-971bd4b4f3f0" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_94a06a2e-8f38-4b6f-b5f7-5910a44c3612" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_9d47d455-6e7b-43a0-ac79-fa04b918112c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_0a46f8f6-75ce-41f7-abf0-34296ddb06b8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAociCurrentPeriodTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_9d47d455-6e7b-43a0-ac79-fa04b918112c" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_0a46f8f6-75ce-41f7-abf0-34296ddb06b8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_b6e359d9-eff3-4fb3-af74-47ae54d5d032" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_9d47d455-6e7b-43a0-ac79-fa04b918112c" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_b6e359d9-eff3-4fb3-af74-47ae54d5d032" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/SecuritiesScheduleofDebtSecuritiesComponentsDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#SecuritiesScheduleofDebtSecuritiesComponentsDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/SecuritiesScheduleofDebtSecuritiesComponentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss_6ebef382-7ed5-4585-b4c2-16187dbeab66" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_0cbc4b16-4067-480a-b5cc-ade94ac5d9a9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss_6ebef382-7ed5-4585-b4c2-16187dbeab66" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_0cbc4b16-4067-480a-b5cc-ade94ac5d9a9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_18d0e405-2ba3-404b-a341-c47bbd645470" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss_6ebef382-7ed5-4585-b4c2-16187dbeab66" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_18d0e405-2ba3-404b-a341-c47bbd645470" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_a8335b68-474c-4c90-a550-35957bcef861" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss_6ebef382-7ed5-4585-b4c2-16187dbeab66" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_a8335b68-474c-4c90-a550-35957bcef861" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_37821239-7182-4869-a0dc-fc724ea818da" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_05b28936-d982-45da-a4b3-c405f497c068" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_37821239-7182-4869-a0dc-fc724ea818da" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_05b28936-d982-45da-a4b3-c405f497c068" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_78bb56be-410b-401b-b44d-52311a4a1911" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_37821239-7182-4869-a0dc-fc724ea818da" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_78bb56be-410b-401b-b44d-52311a4a1911" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_d801dae6-3d09-4958-8789-b08df5eeac3b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_37821239-7182-4869-a0dc-fc724ea818da" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_d801dae6-3d09-4958-8789-b08df5eeac3b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/SecuritiesUnrealizedLossonSecuritiesDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#SecuritiesUnrealizedLossonSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/SecuritiesUnrealizedLossonSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_8385693a-de74-446b-98a5-ffb2e519e651" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_681cb7c7-2035-4aec-ba0e-d47de7e6e366" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_8385693a-de74-446b-98a5-ffb2e519e651" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_681cb7c7-2035-4aec-ba0e-d47de7e6e366" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_196841f4-9233-4607-8515-29f4feb445fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_8385693a-de74-446b-98a5-ffb2e519e651" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_196841f4-9233-4607-8515-29f4feb445fc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_06a14d3e-1668-449b-a586-795e24091c21" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_8e1e34ae-5c46-42f8-a6b8-8344c05ea155" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_06a14d3e-1668-449b-a586-795e24091c21" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_8e1e34ae-5c46-42f8-a6b8-8344c05ea155" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_3dc809c1-265f-4e52-ab47-e5e6e07f2082" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_06a14d3e-1668-449b-a586-795e24091c21" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_3dc809c1-265f-4e52-ab47-e5e6e07f2082" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/SecuritiesInterestIncomeonSecuritiesDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#SecuritiesInterestIncomeonSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/SecuritiesInterestIncomeonSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndOtherIncome_dfc19e31-4873-4f96-8ce2-eb256e8bd468" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndOtherIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesCorporateDebtOperating_3850ab0c-9cac-4e15-8102-566696df9122" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesCorporateDebtOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndOtherIncome_dfc19e31-4873-4f96-8ce2-eb256e8bd468" xlink:to="loc_us-gaap_InterestIncomeSecuritiesCorporateDebtOperating_3850ab0c-9cac-4e15-8102-566696df9122" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesStateAndMunicipal_835ab128-ab0d-4e46-94ff-6595eb343d91" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesStateAndMunicipal"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndOtherIncome_dfc19e31-4873-4f96-8ce2-eb256e8bd468" xlink:to="loc_us-gaap_InterestIncomeSecuritiesStateAndMunicipal_835ab128-ab0d-4e46-94ff-6595eb343d91" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesMortgageBacked_be716b74-aa1d-4b01-a8a8-ad97aae8f178" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesMortgageBacked"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndOtherIncome_dfc19e31-4873-4f96-8ce2-eb256e8bd468" xlink:to="loc_us-gaap_InterestIncomeSecuritiesMortgageBacked_be716b74-aa1d-4b01-a8a8-ad97aae8f178" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesUSTreasuryAndOtherUSGovernment_7c60653d-ad60-467c-b6bf-1a245a96266f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeSecuritiesUSTreasuryAndOtherUSGovernment"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndOtherIncome_dfc19e31-4873-4f96-8ce2-eb256e8bd468" xlink:to="loc_us-gaap_InterestIncomeSecuritiesUSTreasuryAndOtherUSGovernment_7c60653d-ad60-467c-b6bf-1a245a96266f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/SecuritiesAmortizedCostandEstimatedFairValueofInvestmentsinDebtSecuritiesbyContractualMaturityDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#SecuritiesAmortizedCostandEstimatedFairValueofInvestmentsinDebtSecuritiesbyContractualMaturityDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/SecuritiesAmortizedCostandEstimatedFairValueofInvestmentsinDebtSecuritiesbyContractualMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_a8b2fdb7-9b65-45a7-a318-89fb60c1daa2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis_00233e6e-236f-4796-b43b-9b370129952c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_a8b2fdb7-9b65-45a7-a318-89fb60c1daa2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis_00233e6e-236f-4796-b43b-9b370129952c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis_cf165f59-38f8-4abe-b367-ffc8e1af2da2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_a8b2fdb7-9b65-45a7-a318-89fb60c1daa2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis_cf165f59-38f8-4abe-b367-ffc8e1af2da2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis_47e9f4a5-a084-4fa1-8211-50196bc68f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_a8b2fdb7-9b65-45a7-a318-89fb60c1daa2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis_47e9f4a5-a084-4fa1-8211-50196bc68f9d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis_6594dbb9-7593-4d1a-9813-03fbbff83372" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_a8b2fdb7-9b65-45a7-a318-89fb60c1daa2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis_6594dbb9-7593-4d1a-9813-03fbbff83372" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_52fd3d03-f4c5-42f1-8aa7-cc3d7f241b10" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_66e82035-0180-403d-acd4-bd9e4e48e0f5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_52fd3d03-f4c5-42f1-8aa7-cc3d7f241b10" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_66e82035-0180-403d-acd4-bd9e4e48e0f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_32bbfd39-0157-4013-8ebb-d491374c9145" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_52fd3d03-f4c5-42f1-8aa7-cc3d7f241b10" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_32bbfd39-0157-4013-8ebb-d491374c9145" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_52414729-988b-46a7-927e-a8a5bac00c2e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_13945e9b-1356-4386-a527-657fed225af2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_52414729-988b-46a7-927e-a8a5bac00c2e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_13945e9b-1356-4386-a527-657fed225af2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue_3bceda45-fdfe-4eef-a6c6-ccea3ed188dc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_52414729-988b-46a7-927e-a8a5bac00c2e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue_3bceda45-fdfe-4eef-a6c6-ccea3ed188dc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue_21f35612-e678-48b5-b087-8d67ee929f63" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_52414729-988b-46a7-927e-a8a5bac00c2e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue_21f35612-e678-48b5-b087-8d67ee929f63" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue_99a62a7d-8903-42a7-b2bd-ffc74727d522" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_52414729-988b-46a7-927e-a8a5bac00c2e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue_99a62a7d-8903-42a7-b2bd-ffc74727d522" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_72cf23cc-9eed-4a2f-927a-7ac5b7e3ca8c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost_bbeb8a2b-5efe-48ba-9121-1baf88bb07ff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_72cf23cc-9eed-4a2f-927a-7ac5b7e3ca8c" xlink:to="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost_bbeb8a2b-5efe-48ba-9121-1baf88bb07ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost_bee92c45-00db-4fa6-bc8d-7d1eefa7ba80" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_72cf23cc-9eed-4a2f-927a-7ac5b7e3ca8c" xlink:to="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost_bee92c45-00db-4fa6-bc8d-7d1eefa7ba80" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost_13aee6a5-5c6b-4277-8d45-7bb9f36fa5ef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_72cf23cc-9eed-4a2f-927a-7ac5b7e3ca8c" xlink:to="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost_13aee6a5-5c6b-4277-8d45-7bb9f36fa5ef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost_40c93fb4-6971-4af7-97de-e0094614b639" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_72cf23cc-9eed-4a2f-927a-7ac5b7e3ca8c" xlink:to="loc_us-gaap_HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost_40c93fb4-6971-4af7-97de-e0094614b639" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_9848d0d0-0fb0-447a-b3e5-ba6b6f1f7971" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_0616b3cb-02fe-4abe-9606-9e5a41590d5f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_9848d0d0-0fb0-447a-b3e5-ba6b6f1f7971" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_0616b3cb-02fe-4abe-9606-9e5a41590d5f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount_cb92bc65-781b-4c9a-bdd1-a1a345da4ee6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_9848d0d0-0fb0-447a-b3e5-ba6b6f1f7971" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount_cb92bc65-781b-4c9a-bdd1-a1a345da4ee6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_8616471b-329c-451f-a59e-b4b6b42d5d77" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_95fde2fb-af3f-4ba8-92d4-8cb6f7ff6a7c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesFairValue_8616471b-329c-451f-a59e-b4b6b42d5d77" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_95fde2fb-af3f-4ba8-92d4-8cb6f7ff6a7c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_0e5ff6de-9eb4-4030-b346-b2e136fa45bd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesFairValue_8616471b-329c-451f-a59e-b4b6b42d5d77" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_0e5ff6de-9eb4-4030-b346-b2e136fa45bd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_3f79b1b6-e597-4fee-9562-f78fd88bf0a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_7eca472d-5e76-44ab-a2c1-741a30de2ff7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_3f79b1b6-e597-4fee-9562-f78fd88bf0a2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_7eca472d-5e76-44ab-a2c1-741a30de2ff7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue_3564fa2b-bd8f-4983-9a77-9b2e4368e8b1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_3f79b1b6-e597-4fee-9562-f78fd88bf0a2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue_3564fa2b-bd8f-4983-9a77-9b2e4368e8b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue_a00c6178-94d0-44a4-a84f-6078715fce77" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_3f79b1b6-e597-4fee-9562-f78fd88bf0a2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue_a00c6178-94d0-44a4-a84f-6078715fce77" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue_300874d3-b12a-4c9e-9ce3-c070316eafae" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_3f79b1b6-e597-4fee-9562-f78fd88bf0a2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue_300874d3-b12a-4c9e-9ce3-c070316eafae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_dae63d60-d6d7-45fc-8fd9-59a39dab4027" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_5d047741-e7b6-469b-8656-48c5677033b3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_dae63d60-d6d7-45fc-8fd9-59a39dab4027" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_5d047741-e7b6-469b-8656-48c5677033b3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_cffbae2d-822b-4394-bc1b-da60fc5a9e83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_dae63d60-d6d7-45fc-8fd9-59a39dab4027" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_cffbae2d-822b-4394-bc1b-da60fc5a9e83" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/SecuritiesUnrealizedandRealizedGainLossRecognizedinNetIncomeonEquityInvestmentsDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#SecuritiesUnrealizedandRealizedGainLossRecognizedinNetIncomeonEquityInvestmentsDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/SecuritiesUnrealizedandRealizedGainLossRecognizedinNetIncomeonEquityInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_c6d54e6a-466d-4805-87fb-b4ceacb3ad5c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfInvestments_fb99458e-f026-45d1-aab2-bbbe04dc70b6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnSaleOfInvestments"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RealizedInvestmentGainsLosses_c6d54e6a-466d-4805-87fb-b4ceacb3ad5c" xlink:to="loc_us-gaap_GainLossOnSaleOfInvestments_fb99458e-f026-45d1-aab2-bbbe04dc70b6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_411f2af2-de7c-4dd0-9744-29a1734e666b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RealizedInvestmentGainsLosses_c6d54e6a-466d-4805-87fb-b4ceacb3ad5c" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_411f2af2-de7c-4dd0-9744-29a1734e666b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/LoansandAllowanceforLoanLossesNonperformingAssetsbyAssetClassDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#LoansandAllowanceforLoanLossesNonperformingAssetsbyAssetClassDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/LoansandAllowanceforLoanLossesNonperformingAssetsbyAssetClassDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_sbsi_FinancingReceivableNonperformingAndRepossessedAssets_c2eb4b01-5339-4a3d-b55c-29e50ba919e2" xlink:href="sbsi-20220331.xsd#sbsi_FinancingReceivableNonperformingAndRepossessedAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAcquiredThroughForeclosure_9deb4d1f-b5d1-4397-8625-95ee95ea74e0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RealEstateAcquiredThroughForeclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sbsi_FinancingReceivableNonperformingAndRepossessedAssets_c2eb4b01-5339-4a3d-b55c-29e50ba919e2" xlink:to="loc_us-gaap_RealEstateAcquiredThroughForeclosure_9deb4d1f-b5d1-4397-8625-95ee95ea74e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_612b4dca-a91c-4532-bf40-b8f2e265e10d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sbsi_FinancingReceivableNonperformingAndRepossessedAssets_c2eb4b01-5339-4a3d-b55c-29e50ba919e2" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_612b4dca-a91c-4532-bf40-b8f2e265e10d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationsRecordedInvestment_9c9301a0-ba67-4302-8b89-d0b5493a4dfc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableModificationsRecordedInvestment"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sbsi_FinancingReceivableNonperformingAndRepossessedAssets_c2eb4b01-5339-4a3d-b55c-29e50ba919e2" xlink:to="loc_us-gaap_FinancingReceivableModificationsRecordedInvestment_9c9301a0-ba67-4302-8b89-d0b5493a4dfc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing_c2d9bb2d-e93e-47f4-ae0e-c222992f37b8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sbsi_FinancingReceivableNonperformingAndRepossessedAssets_c2eb4b01-5339-4a3d-b55c-29e50ba919e2" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing_c2d9bb2d-e93e-47f4-ae0e-c222992f37b8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherForeclosedAssets_6a351632-2ccb-41a5-a2a5-86c5b1189877" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherForeclosedAssets"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sbsi_FinancingReceivableNonperformingAndRepossessedAssets_c2eb4b01-5339-4a3d-b55c-29e50ba919e2" xlink:to="loc_us-gaap_OtherForeclosedAssets_6a351632-2ccb-41a5-a2a5-86c5b1189877" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/LoansandAllowanceforLoanLossesAllowanceforLoanLossesActivitybyPortfolioSegmentDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#LoansandAllowanceforLoanLossesAllowanceforLoanLossesActivitybyPortfolioSegmentDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/LoansandAllowanceforLoanLossesAllowanceforLoanLossesActivitybyPortfolioSegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery_879af192-e717-440e-8f56-47cb6429426c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_1e4bce07-8331-4aac-914e-103a877be907" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery_879af192-e717-440e-8f56-47cb6429426c" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_1e4bce07-8331-4aac-914e-103a877be907" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_088dd9fe-05b1-4848-b1a4-3da23130032f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery_879af192-e717-440e-8f56-47cb6429426c" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_088dd9fe-05b1-4848-b1a4-3da23130032f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/EmployeeBenefitPlansDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#EmployeeBenefitPlansDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/EmployeeBenefitPlansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_50de3f88-6d67-4026-9c06-ac6ba3face40" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_50de3f88-6d67-4026-9c06-ac6ba3face40" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_51e81366-bcc5-4806-b5c8-f3692af61881" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_51e81366-bcc5-4806-b5c8-f3692af61881" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_cf25b66b-cb30-4b29-a736-7e3eec12c38e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_cf25b66b-cb30-4b29-a736-7e3eec12c38e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_80310d7a-d017-4874-bad5-87dbba2272e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_80310d7a-d017-4874-bad5-87dbba2272e9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_ccad8043-fa68-4d75-9e18-ef56c0505e19" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_ccad8043-fa68-4d75-9e18-ef56c0505e19" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_d6cdeb28-de5a-4b44-87d1-78d0f68976e2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9d514273-67fe-45f0-b604-568a3ca0c573" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_d6cdeb28-de5a-4b44-87d1-78d0f68976e2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleOfDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#DerivativeFinancialInstrumentsandHedgingActivitiesScheduleOfDerivativeInstrumentsDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleOfDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_441e3203-d580-4b4e-ba4e-714650b748a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_41ba76b6-c4c3-47d0-9f87-e097be11bfce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_441e3203-d580-4b4e-ba4e-714650b748a8" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_41ba76b6-c4c3-47d0-9f87-e097be11bfce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueGrossAsset_777581d1-b7dc-43fc-aea5-fa3a81066925" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilityFairValueGrossAsset"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_441e3203-d580-4b4e-ba4e-714650b748a8" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueGrossAsset_777581d1-b7dc-43fc-aea5-fa3a81066925" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_fc4397d3-6236-4606-a43d-e0fd3cbe9b4a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_441e3203-d580-4b4e-ba4e-714650b748a8" xlink:to="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_fc4397d3-6236-4606-a43d-e0fd3cbe9b4a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_9f068511-0e22-4b3f-ab0c-0b1fbdba4cba" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_10f4d35f-cd9f-4aa4-a42d-16160e8b937a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssets_9f068511-0e22-4b3f-ab0c-0b1fbdba4cba" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_10f4d35f-cd9f-4aa4-a42d-16160e8b937a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueGrossLiability_b0321928-9d1b-43d1-93dd-d2e05e35cedf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetFairValueGrossLiability"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssets_9f068511-0e22-4b3f-ab0c-0b1fbdba4cba" xlink:to="loc_us-gaap_DerivativeAssetFairValueGrossLiability_b0321928-9d1b-43d1-93dd-d2e05e35cedf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetCollateralObligationToReturnCashOffset_73c80c13-f5d9-49b0-9733-b1d25cc92333" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetCollateralObligationToReturnCashOffset"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssets_9f068511-0e22-4b3f-ab0c-0b1fbdba4cba" xlink:to="loc_us-gaap_DerivativeAssetCollateralObligationToReturnCashOffset_73c80c13-f5d9-49b0-9733-b1d25cc92333" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.southside.com/role/IncomeTaxesProvisionforIncomeTaxesDetails" xlink:type="simple" xlink:href="sbsi-20220331.xsd#IncomeTaxesProvisionforIncomeTaxesDetails"/>
  <link:calculationLink xlink:role="http://www.southside.com/role/IncomeTaxesProvisionforIncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_3e2d7f01-00cf-4cce-93ac-fc91b8e202db" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_8e49e084-5796-4f9c-9617-8fee37aa2a38" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_3e2d7f01-00cf-4cce-93ac-fc91b8e202db" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_8e49e084-5796-4f9c-9617-8fee37aa2a38" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_6a6d8d79-6083-42ba-9088-73e82dc7f9e9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_3e2d7f01-00cf-4cce-93ac-fc91b8e202db" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_6a6d8d79-6083-42ba-9088-73e82dc7f9e9" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
