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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:31860316-45ee-405a-ad04-53281225de0d,g:0c98d3c1-bc5a-4bde-8152-ac4f037c09a1-->
<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" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.renasantbank.com/role/ConsolidatedStatementsofChangesinShareholdersEquity" xlink:type="simple" xlink:href="rnst-20250930.xsd#ConsolidatedStatementsofChangesinShareholdersEquity"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/ConsolidatedStatementsofChangesinShareholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_60468332-2a21-493d-9569-4d7ca7d0fc33" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_ae47016d-4c03-4585-82a5-8f2266f70312" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_60468332-2a21-493d-9569-4d7ca7d0fc33" xlink:to="loc_us-gaap_StatementTable_ae47016d-4c03-4585-82a5-8f2266f70312" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7bcae3c0-7c18-4285-8e22-7da0f7e1d245" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ae47016d-4c03-4585-82a5-8f2266f70312" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7bcae3c0-7c18-4285-8e22-7da0f7e1d245" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7bcae3c0-7c18-4285-8e22-7da0f7e1d245_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7bcae3c0-7c18-4285-8e22-7da0f7e1d245" xlink:to="loc_us-gaap_EquityComponentDomain_7bcae3c0-7c18-4285-8e22-7da0f7e1d245_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7bcae3c0-7c18-4285-8e22-7da0f7e1d245" xlink:to="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_75f290e0-c79b-43a3-8dbf-9f4b8c122bf1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:to="loc_us-gaap_CommonStockMember_75f290e0-c79b-43a3-8dbf-9f4b8c122bf1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_e53aca4c-3abb-41e8-8124-4cc178bb4afd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:to="loc_us-gaap_TreasuryStockCommonMember_e53aca4c-3abb-41e8-8124-4cc178bb4afd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_999ca5ea-aded-4aee-8f99-e8fee7df9c12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_999ca5ea-aded-4aee-8f99-e8fee7df9c12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_e24c0436-f1c6-4c21-8612-d7082336720e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:to="loc_us-gaap_RetainedEarningsMember_e24c0436-f1c6-4c21-8612-d7082336720e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_a6004453-913d-4c39-b6b4-fb84bea231b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_0c904cc2-2bae-4621-ac3b-c03463d85e19" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_a6004453-913d-4c39-b6b4-fb84bea231b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_60468332-2a21-493d-9569-4d7ca7d0fc33" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_ffe0d454-26d7-4cfb-af3f-6f37ebe017df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_ffe0d454-26d7-4cfb-af3f-6f37ebe017df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_59254ecb-8751-4276-93a0-d90802490fb1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockholdersEquity_59254ecb-8751-4276-93a0-d90802490fb1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_ae94b0aa-a7c2-4853-86ce-aae9014a4ec7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_NetIncomeLoss_ae94b0aa-a7c2-4853-86ce-aae9014a4ec7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_149b492e-ef98-4490-a61c-3698d9b2ac76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_149b492e-ef98-4490-a61c-3698d9b2ac76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_4c331046-9c9d-40a7-b29e-2f17c0642a14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_4c331046-9c9d-40a7-b29e-2f17c0642a14" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_af66460e-9e92-445c-a71d-2c2b3df5780f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_DividendsCommonStockCash_af66460e-9e92-445c-a71d-2c2b3df5780f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_5c2d0e95-409a-4b16-a66f-197219b22490" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_5c2d0e95-409a-4b16-a66f-197219b22490" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_13756532-bb05-4aae-a750-2ffccac38a91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_13756532-bb05-4aae-a750-2ffccac38a91" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_AdditionalPaidInCapitalIssuanceOfStockAcquisitionMeasurementPeriodAdjustment_7290f291-c72e-4507-a769-d5e6e9d16a5b" xlink:href="rnst-20250930.xsd#rnst_AdditionalPaidInCapitalIssuanceOfStockAcquisitionMeasurementPeriodAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_rnst_AdditionalPaidInCapitalIssuanceOfStockAcquisitionMeasurementPeriodAdjustment_7290f291-c72e-4507-a769-d5e6e9d16a5b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_1bbd22b6-818a-4b9c-9211-4dcbab55a3b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_1bbd22b6-818a-4b9c-9211-4dcbab55a3b7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_9856cb3e-b5cd-4f14-a989-8af19ceebd02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_9856cb3e-b5cd-4f14-a989-8af19ceebd02" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_265c0ece-f3b0-40ae-83fb-994c0bc0976a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_265c0ece-f3b0-40ae-83fb-994c0bc0976a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_ad63f0f9-a1ca-448e-9fcf-add1dab7acc0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_ad63f0f9-a1ca-448e-9fcf-add1dab7acc0" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_93efb8cc-945f-4f60-a596-5ca687b99c4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7a53c0e0-c813-4fcf-a868-eca6ce021fb3" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_93efb8cc-945f-4f60-a596-5ca687b99c4a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_4ae2cedc-15a1-4bab-b101-cecd3c7a9a2a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_ac2dc890-8e33-4d8d-adea-8a53ea0d92ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/MergersandAcquisitionsNarrativeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#MergersandAcquisitionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/MergersandAcquisitionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1dff317d-e19d-41cb-9fb5-4ca42e98916e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1dff317d-e19d-41cb-9fb5-4ca42e98916e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_3aa6a083-c640-49b5-a418-11cca7ec5502" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1dff317d-e19d-41cb-9fb5-4ca42e98916e" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_3aa6a083-c640-49b5-a418-11cca7ec5502" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3aa6a083-c640-49b5-a418-11cca7ec5502_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_3aa6a083-c640-49b5-a418-11cca7ec5502" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3aa6a083-c640-49b5-a418-11cca7ec5502_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07e2df57-20fd-48fb-8955-a5e565eb744e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_3aa6a083-c640-49b5-a418-11cca7ec5502" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07e2df57-20fd-48fb-8955-a5e565eb744e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstMember_69b123d6-b824-4e3b-9682-df29be0b4d98" xlink:href="rnst-20250930.xsd#rnst_TheFirstMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07e2df57-20fd-48fb-8955-a5e565eb744e" xlink:to="loc_rnst_TheFirstMember_69b123d6-b824-4e3b-9682-df29be0b4d98" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstFairValueMember_4797177f-0d47-4698-9ef1-631572d03114" xlink:href="rnst-20250930.xsd#rnst_TheFirstFairValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_07e2df57-20fd-48fb-8955-a5e565eb744e" xlink:to="loc_rnst_TheFirstFairValueMember_4797177f-0d47-4698-9ef1-631572d03114" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_2f527493-6507-450c-a539-535da8cdc4fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1dff317d-e19d-41cb-9fb5-4ca42e98916e" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_2f527493-6507-450c-a539-535da8cdc4fe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_2f527493-6507-450c-a539-535da8cdc4fe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_2f527493-6507-450c-a539-535da8cdc4fe" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_2f527493-6507-450c-a539-535da8cdc4fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_e3d06c8c-04be-4689-9079-9863cac4142b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_2f527493-6507-450c-a539-535da8cdc4fe" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_e3d06c8c-04be-4689-9079-9863cac4142b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankAdvancesMember_56c3d97f-5e73-452b-8a47-58605b269703" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalHomeLoanBankAdvancesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_e3d06c8c-04be-4689-9079-9863cac4142b" xlink:to="loc_us-gaap_FederalHomeLoanBankAdvancesMember_56c3d97f-5e73-452b-8a47-58605b269703" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_a2ce3a32-a972-49cf-be44-02cd189d2318" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1dff317d-e19d-41cb-9fb5-4ca42e98916e" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_a2ce3a32-a972-49cf-be44-02cd189d2318" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a2ce3a32-a972-49cf-be44-02cd189d2318_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a2ce3a32-a972-49cf-be44-02cd189d2318" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a2ce3a32-a972-49cf-be44-02cd189d2318_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_b165889d-782d-49b5-b6d6-76ab9c72a59d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a2ce3a32-a972-49cf-be44-02cd189d2318" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_b165889d-782d-49b5-b6d6-76ab9c72a59d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebtMember_efab2277-bf82-4d22-8cc2-709f807e79be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_b165889d-782d-49b5-b6d6-76ab9c72a59d" xlink:to="loc_us-gaap_SubordinatedDebtMember_efab2277-bf82-4d22-8cc2-709f807e79be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_JuniorSubordinatedDebtMember_f64793b6-6f5d-49dd-9b36-e1981ccbf81d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_JuniorSubordinatedDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_b165889d-782d-49b5-b6d6-76ab9c72a59d" xlink:to="loc_us-gaap_JuniorSubordinatedDebtMember_f64793b6-6f5d-49dd-9b36-e1981ccbf81d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_58244ef5-1928-423a-a740-e83db4f9fce8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_58244ef5-1928-423a-a740-e83db4f9fce8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_43314bff-afef-42a7-8751-c9a568446d7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_43314bff-afef-42a7-8751-c9a568446d7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PaymentstoAcquireBusinessesSettlementforStockOptions_b677ce6a-2cae-438d-95b5-28ac0df0c317" xlink:href="rnst-20250930.xsd#rnst_PaymentstoAcquireBusinessesSettlementforStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_rnst_PaymentstoAcquireBusinessesSettlementforStockOptions_b677ce6a-2cae-438d-95b5-28ac0df0c317" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_6077d944-bb8a-4f9d-b6cd-359df45cc917" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_6077d944-bb8a-4f9d-b6cd-359df45cc917" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationNumberofLocationsAcquired_06dacc1f-04cf-415f-aff2-5338db0c4121" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationNumberofLocationsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_rnst_BusinessCombinationNumberofLocationsAcquired_06dacc1f-04cf-415f-aff2-5338db0c4121" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_2ca1147d-20a6-417f-ac62-b158b3d23c57" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_2ca1147d-20a6-417f-ac62-b158b3d23c57" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedIntangibleAssetsIncludingGoodwill_d4c91932-15b0-479f-a6ad-43155a3fad72" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedIntangibleAssetsIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedIntangibleAssetsIncludingGoodwill_d4c91932-15b0-479f-a6ad-43155a3fad72" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_0c44eac8-40da-4ac8-8ef3-9fbe976d5f52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_Goodwill_0c44eac8-40da-4ac8-8ef3-9fbe976d5f52" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_3977f342-a20b-44e2-85dc-eb586768f342" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_3977f342-a20b-44e2-85dc-eb586768f342" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_67324b4e-7e48-493c-ac88-1a244a24f99c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_67324b4e-7e48-493c-ac88-1a244a24f99c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GoodwillPriorToMeasurementPeriodAdjustment_9b48169c-6345-471c-9e4e-69b88dc65704" xlink:href="rnst-20250930.xsd#rnst_GoodwillPriorToMeasurementPeriodAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_rnst_GoodwillPriorToMeasurementPeriodAdjustment_9b48169c-6345-471c-9e4e-69b88dc65704" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_0a4d38bb-1e4c-4da8-b725-9950731d131e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_0a4d38bb-1e4c-4da8-b725-9950731d131e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt_0d61b250-bd64-4ae6-8c5a-059b69ac159d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesLongTermDebt_0d61b250-bd64-4ae6-8c5a-059b69ac159d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_fa9d7930-4488-4f1e-be4d-87cf4ef8e346" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_fa9d7930-4488-4f1e-be4d-87cf4ef8e346" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationCreditProvisionExpense_7bedaf68-5df8-43c2-a884-f2285e6ae706" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationCreditProvisionExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b7729d7-13b6-44f0-9926-1bfb718ffc2c" xlink:to="loc_rnst_BusinessCombinationCreditProvisionExpense_7bedaf68-5df8-43c2-a884-f2285e6ae706" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/MergersandAcquisitionsSummaryoftheAllocationofPurchasePricetoAssetsandLiabilitiesAcquiredDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#MergersandAcquisitionsSummaryoftheAllocationofPurchasePricetoAssetsandLiabilitiesAcquiredDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/MergersandAcquisitionsSummaryoftheAllocationofPurchasePricetoAssetsandLiabilitiesAcquiredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_160ed398-4824-4ce9-82f6-e1b56e9e99f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f8bf36b5-4d9b-4a03-9fde-bb444f633d78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_160ed398-4824-4ce9-82f6-e1b56e9e99f6" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f8bf36b5-4d9b-4a03-9fde-bb444f633d78" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_3afce30f-58d3-402e-8f1c-32182452c90b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f8bf36b5-4d9b-4a03-9fde-bb444f633d78" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_3afce30f-58d3-402e-8f1c-32182452c90b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3afce30f-58d3-402e-8f1c-32182452c90b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_3afce30f-58d3-402e-8f1c-32182452c90b" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_3afce30f-58d3-402e-8f1c-32182452c90b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2bf29a2d-8423-46ab-ba22-25abbbef9d29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_3afce30f-58d3-402e-8f1c-32182452c90b" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2bf29a2d-8423-46ab-ba22-25abbbef9d29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstMember_5d88c17d-d593-41be-86a5-ed95c7fabaed" xlink:href="rnst-20250930.xsd#rnst_TheFirstMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2bf29a2d-8423-46ab-ba22-25abbbef9d29" xlink:to="loc_rnst_TheFirstMember_5d88c17d-d593-41be-86a5-ed95c7fabaed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_160ed398-4824-4ce9-82f6-e1b56e9e99f6" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_fb5e5550-ec18-46e9-a7c8-da9280892f6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_fb5e5550-ec18-46e9-a7c8-da9280892f6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionSharePrice_3e0f979d-7c4a-4daf-90a0-749e9da7d2fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionSharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:to="loc_us-gaap_BusinessAcquisitionSharePrice_3e0f979d-7c4a-4daf-90a0-749e9da7d2fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_cd9aaf4d-ea7b-4b15-ba90-adfd61357d3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_cd9aaf4d-ea7b-4b15-ba90-adfd61357d3b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PostAcquisitionCompensationCostOnUnvestedRestrictedStockAwards_0ae50eb1-c61a-4f78-a65d-2543ab7bf5da" xlink:href="rnst-20250930.xsd#rnst_PostAcquisitionCompensationCostOnUnvestedRestrictedStockAwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:to="loc_rnst_PostAcquisitionCompensationCostOnUnvestedRestrictedStockAwards_0ae50eb1-c61a-4f78-a65d-2543ab7bf5da" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PaymentstoAcquireBusinessesSettlementforStockOptions_dba13935-ea08-4ed9-aef6-6dbe2e69f56a" xlink:href="rnst-20250930.xsd#rnst_PaymentstoAcquireBusinessesSettlementforStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:to="loc_rnst_PaymentstoAcquireBusinessesSettlementforStockOptions_dba13935-ea08-4ed9-aef6-6dbe2e69f56a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_9bba8a56-828f-463f-a10b-16477d73f5ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationConsiderationTransferredAbstract_7b937a99-b646-4276-a2bb-4a70ce02d098" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_9bba8a56-828f-463f-a10b-16477d73f5ec" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/MergersandAcquisitionsSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#MergersandAcquisitionsSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/MergersandAcquisitionsSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a0b45eff-e95d-4a9d-95db-81d261554ccb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a0b45eff-e95d-4a9d-95db-81d261554ccb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_be92b243-d7cc-4008-a63a-ed7d87e33680" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a0b45eff-e95d-4a9d-95db-81d261554ccb" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_be92b243-d7cc-4008-a63a-ed7d87e33680" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_be92b243-d7cc-4008-a63a-ed7d87e33680_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_be92b243-d7cc-4008-a63a-ed7d87e33680" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_be92b243-d7cc-4008-a63a-ed7d87e33680_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c9fde23a-6f57-4067-b937-b6b15e1d0328" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_be92b243-d7cc-4008-a63a-ed7d87e33680" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c9fde23a-6f57-4067-b937-b6b15e1d0328" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstMember_2fd95f57-1cd7-4871-9c72-678c937b2133" xlink:href="rnst-20250930.xsd#rnst_TheFirstMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c9fde23a-6f57-4067-b937-b6b15e1d0328" xlink:to="loc_rnst_TheFirstMember_2fd95f57-1cd7-4871-9c72-678c937b2133" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstFairValueMember_b79ed48f-7adf-4c10-bb6e-4883665f8e65" xlink:href="rnst-20250930.xsd#rnst_TheFirstFairValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c9fde23a-6f57-4067-b937-b6b15e1d0328" xlink:to="loc_rnst_TheFirstFairValueMember_b79ed48f-7adf-4c10-bb6e-4883665f8e65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_35716947-da7d-4324-8937-6e91ef8c4f17" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a0b45eff-e95d-4a9d-95db-81d261554ccb" xlink:to="loc_srt_RestatementAxis_35716947-da7d-4324-8937-6e91ef8c4f17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_35716947-da7d-4324-8937-6e91ef8c4f17_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_35716947-da7d-4324-8937-6e91ef8c4f17" xlink:to="loc_srt_RestatementDomain_35716947-da7d-4324-8937-6e91ef8c4f17_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_6d3d6a19-38bf-4ed5-889d-f6de3619d7fc" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_35716947-da7d-4324-8937-6e91ef8c4f17" xlink:to="loc_srt_RestatementDomain_6d3d6a19-38bf-4ed5-889d-f6de3619d7fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PreliminaryAdjustmentsMember_69d80eaa-1ef5-4c74-9818-07b056af1400" xlink:href="rnst-20250930.xsd#rnst_PreliminaryAdjustmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_6d3d6a19-38bf-4ed5-889d-f6de3619d7fc" xlink:to="loc_rnst_PreliminaryAdjustmentsMember_69d80eaa-1ef5-4c74-9818-07b056af1400" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_MeasurementPeriodAdjustmentsMember_1bec26ae-d0ad-4357-bdd6-7ca54562c0af" xlink:href="rnst-20250930.xsd#rnst_MeasurementPeriodAdjustmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_6d3d6a19-38bf-4ed5-889d-f6de3619d7fc" xlink:to="loc_rnst_MeasurementPeriodAdjustmentsMember_1bec26ae-d0ad-4357-bdd6-7ca54562c0af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_7c178e6c-23e0-49d5-a853-d7960cb66dbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_7c178e6c-23e0-49d5-a853-d7960cb66dbd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_06817e97-9268-4920-b40e-d033fb9b9463" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_06817e97-9268-4920-b40e-d033fb9b9463" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansNet_11295b47-9776-4f16-b82b-e67464f7001b" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansNet_11295b47-9776-4f16-b82b-e67464f7001b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_7ec0a32a-5451-4ebe-bf59-538a42b48ac6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_7ec0a32a-5451-4ebe-bf59-538a42b48ac6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance_2bc69924-895f-40a2-b7cd-d69df50edf62" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_rnst_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance_2bc69924-895f-40a2-b7cd-d69df50edf62" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationRecognizedAssetAcquiredOtherRealEstateOwned_1a9f8332-1a53-4a7a-a085-84b2746cdeae" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationRecognizedAssetAcquiredOtherRealEstateOwned"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_rnst_BusinessCombinationRecognizedAssetAcquiredOtherRealEstateOwned_1a9f8332-1a53-4a7a-a085-84b2746cdeae" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_ad7d262a-8a57-47a3-84ad-88261ad45696" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_ad7d262a-8a57-47a3-84ad-88261ad45696" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_3201c21c-9edd-43ed-81a9-0d5058ece50a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_3201c21c-9edd-43ed-81a9-0d5058ece50a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_807a972b-e430-4b5e-b94f-b23626155c16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_807a972b-e430-4b5e-b94f-b23626155c16" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeposits_eee3cea3-ac5c-4b17-aa72-6079428eac2a" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_rnst_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeposits_eee3cea3-ac5c-4b17-aa72-6079428eac2a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_508b961f-3940-40c0-b908-73e3b8367904" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_508b961f-3940-40c0-b908-73e3b8367904" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_5e96c4af-6002-4e15-9a50-d9968a43cdb6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_5e96c4af-6002-4e15-9a50-d9968a43cdb6" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_7e8c83e5-40d9-42a3-88ce-d95bf01dbeed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_7e8c83e5-40d9-42a3-88ce-d95bf01dbeed" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationRecognizedAssetAcquiredToLiabilityAssumedExcessLessAndGoodwillNetOfCashSettlementForStockOptions_9392915a-9312-459f-aa05-dc973b301de2" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationRecognizedAssetAcquiredToLiabilityAssumedExcessLessAndGoodwillNetOfCashSettlementForStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_rnst_BusinessCombinationRecognizedAssetAcquiredToLiabilityAssumedExcessLessAndGoodwillNetOfCashSettlementForStockOptions_9392915a-9312-459f-aa05-dc973b301de2" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_e7db05db-99fa-4bac-bb73-1dbaf7f35e13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_Goodwill_e7db05db-99fa-4bac-bb73-1dbaf7f35e13" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_4c74bae9-4d94-403b-907e-0e6924b46db0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_4c74bae9-4d94-403b-907e-0e6924b46db0" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4fb393e1-c3ac-443d-8a7b-261e30518194" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCashAndCashEquivalents_22a0eafa-36f2-44be-ba2f-0c756ae57e2e" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCashAndCashEquivalents_22a0eafa-36f2-44be-ba2f-0c756ae57e2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentSecurities_a3d08f97-f27c-43bb-a19c-0966df1ed386" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentSecurities_a3d08f97-f27c-43bb-a19c-0966df1ed386" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLoansReceivable_8ce63636-6f39-4684-9e45-d7cbd397080e" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLoansReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLoansReceivable_8ce63636-6f39-4684-9e45-d7cbd397080e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentPremisesAndEquipment_b0eb1c77-146a-493a-89bd-9c045e71aeaa" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentPremisesAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentPremisesAndEquipment_b0eb1c77-146a-493a-89bd-9c045e71aeaa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentBankOwnedLifeInsurance_b56ff325-a1b5-4d5b-869c-77049fd19b06" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentBankOwnedLifeInsurance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentBankOwnedLifeInsurance_b56ff325-a1b5-4d5b-869c-77049fd19b06" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherRealEstateOwned_25fe3cf2-b053-4164-a69c-5fd393b638fd" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherRealEstateOwned"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherRealEstateOwned_25fe3cf2-b053-4164-a69c-5fd393b638fd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles_962b3b17-6722-434b-8f8d-1164ccb4c90a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles_962b3b17-6722-434b-8f8d-1164ccb4c90a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets_a811fd0c-4e01-476b-9036-2eea93c1a9b6" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets_a811fd0c-4e01-476b-9036-2eea93c1a9b6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAssets_00f1aaae-fc9c-40ed-9ccc-53f995b68555" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAssets_00f1aaae-fc9c-40ed-9ccc-53f995b68555" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeposits_fab6a826-18a3-4370-a9a7-14f232ee9419" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeposits_fab6a826-18a3-4370-a9a7-14f232ee9419" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentBorrowings_0c55b6f9-af1b-4450-a095-213d61856b39" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentBorrowings_0c55b6f9-af1b-4450-a095-213d61856b39" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherLiabilities_04840f96-f2f6-4b7f-8538-2ab163747ff6" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherLiabilities_04840f96-f2f6-4b7f-8538-2ab163747ff6" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLiabilities_7393b59a-c907-41c8-8fe1-3ef8dbc84684" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentLiabilities_7393b59a-c907-41c8-8fe1-3ef8dbc84684" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetIdentifiableAssetAcquiredOverLiabilitiesAssumed_054edd06-757e-416d-b6b4-fb1eff9498c5" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetIdentifiableAssetAcquiredOverLiabilitiesAssumed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetIdentifiableAssetAcquiredOverLiabilitiesAssumed_054edd06-757e-416d-b6b4-fb1eff9498c5" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_19c95527-9636-4c7a-b07c-b9443b1afde9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_19c95527-9636-4c7a-b07c-b9443b1afde9" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetIdentifiableAssetAcquiredOverLiabilitiesAssumedAndGoodwill_1a0aa55e-b737-408d-a9b2-4664f60993e6" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetIdentifiableAssetAcquiredOverLiabilitiesAssumedAndGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetAbstract_b900ebf6-5a53-45d7-8480-533624c6af05" xlink:to="loc_rnst_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentNetIdentifiableAssetAcquiredOverLiabilitiesAssumedAndGoodwill_1a0aa55e-b737-408d-a9b2-4664f60993e6" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/MergersandAcquisitionsSummaryofAcquiredLoanPortfolioDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#MergersandAcquisitionsSummaryofAcquiredLoanPortfolioDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/MergersandAcquisitionsSummaryofAcquiredLoanPortfolioDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_06f8393c-7520-4abd-a057-8111af1aed52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a9085154-6904-4052-8d25-205f9a58ef4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_06f8393c-7520-4abd-a057-8111af1aed52" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a9085154-6904-4052-8d25-205f9a58ef4b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_77376631-04ba-41c3-a0fb-92d3e5fc88b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a9085154-6904-4052-8d25-205f9a58ef4b" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_77376631-04ba-41c3-a0fb-92d3e5fc88b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_77376631-04ba-41c3-a0fb-92d3e5fc88b6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_77376631-04ba-41c3-a0fb-92d3e5fc88b6" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_77376631-04ba-41c3-a0fb-92d3e5fc88b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a8153c2c-1fbc-4683-841b-2b27fc96ca02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_77376631-04ba-41c3-a0fb-92d3e5fc88b6" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a8153c2c-1fbc-4683-841b-2b27fc96ca02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstMember_77dd9596-e99a-4265-9c6b-ed3255f48f09" xlink:href="rnst-20250930.xsd#rnst_TheFirstMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a8153c2c-1fbc-4683-841b-2b27fc96ca02" xlink:to="loc_rnst_TheFirstMember_77dd9596-e99a-4265-9c6b-ed3255f48f09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract_63fdf445-2fc2-481d-b6bd-10b84a75c71f" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_06f8393c-7520-4abd-a057-8111af1aed52" xlink:to="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract_63fdf445-2fc2-481d-b6bd-10b84a75c71f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationFairValue_ad1a4070-c06a-42d4-be81-f01c23643eae" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract_63fdf445-2fc2-481d-b6bd-10b84a75c71f" xlink:to="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationFairValue_ad1a4070-c06a-42d4-be81-f01c23643eae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationFinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_24c0e9b7-27ec-4506-9996-e660db02ba86" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationFinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract_63fdf445-2fc2-481d-b6bd-10b84a75c71f" xlink:to="loc_rnst_BusinessCombinationFinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_24c0e9b7-27ec-4506-9996-e660db02ba86" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationNonCreditDiscount_1d8f551a-5aac-4267-a5bb-d05320eeaff7" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationNonCreditDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract_63fdf445-2fc2-481d-b6bd-10b84a75c71f" xlink:to="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationNonCreditDiscount_1d8f551a-5aac-4267-a5bb-d05320eeaff7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAmountAtPurchasePrice_22cf56c1-9dc4-44b3-a015-92307045204c" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAmountAtPurchasePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAbstract_63fdf445-2fc2-481d-b6bd-10b84a75c71f" xlink:to="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithCreditDeteriorationAmountAtPurchasePrice_22cf56c1-9dc4-44b3-a015-92307045204c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithoutCreditDeteriorationAbstract_5c95d568-a0ac-45bc-ac44-c3dbc0cee328" xlink:href="rnst-20250930.xsd#rnst_BusinessCombinationAcquiredReceivablePurchasedWithoutCreditDeteriorationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_06f8393c-7520-4abd-a057-8111af1aed52" xlink:to="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithoutCreditDeteriorationAbstract_5c95d568-a0ac-45bc-ac44-c3dbc0cee328" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_fae4ebae-3180-4427-acf1-68618bc8f97c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithoutCreditDeteriorationAbstract_5c95d568-a0ac-45bc-ac44-c3dbc0cee328" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_fae4ebae-3180-4427-acf1-68618bc8f97c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_838432a6-ff0d-4aec-97e2-e736551682a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithoutCreditDeteriorationAbstract_5c95d568-a0ac-45bc-ac44-c3dbc0cee328" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount_838432a6-ff0d-4aec-97e2-e736551682a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_1291c5a3-8ba5-4008-aed3-5950de8a078a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_BusinessCombinationAcquiredReceivablePurchasedWithoutCreditDeteriorationAbstract_5c95d568-a0ac-45bc-ac44-c3dbc0cee328" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible_1291c5a3-8ba5-4008-aed3-5950de8a078a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/MergersandAcquisitionsProFormaCombinedCondensedConsolidatedFinancialInformationDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#MergersandAcquisitionsProFormaCombinedCondensedConsolidatedFinancialInformationDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/MergersandAcquisitionsProFormaCombinedCondensedConsolidatedFinancialInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_acfe79e4-c860-4efd-8138-19dd118dc9f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_acfe79e4-c860-4efd-8138-19dd118dc9f8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9ade9653-8e76-4582-ad0f-f81c8d44deda" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_acfe79e4-c860-4efd-8138-19dd118dc9f8" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9ade9653-8e76-4582-ad0f-f81c8d44deda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9ade9653-8e76-4582-ad0f-f81c8d44deda_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9ade9653-8e76-4582-ad0f-f81c8d44deda" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9ade9653-8e76-4582-ad0f-f81c8d44deda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8d9aebc9-ebc9-4f53-9e18-4d1972100ccb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9ade9653-8e76-4582-ad0f-f81c8d44deda" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8d9aebc9-ebc9-4f53-9e18-4d1972100ccb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BrandMortgageGroupLLCMember_feccbc27-3755-474b-82e0-4254ed2a6f82" xlink:href="rnst-20250930.xsd#rnst_BrandMortgageGroupLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8d9aebc9-ebc9-4f53-9e18-4d1972100ccb" xlink:to="loc_rnst_BrandMortgageGroupLLCMember_feccbc27-3755-474b-82e0-4254ed2a6f82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessAcquisitionProFormaInterestIncomeNet_9274011e-e434-4aa2-8c35-a29e34581029" xlink:href="rnst-20250930.xsd#rnst_BusinessAcquisitionProFormaInterestIncomeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:to="loc_rnst_BusinessAcquisitionProFormaInterestIncomeNet_9274011e-e434-4aa2-8c35-a29e34581029" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessAcquisitionProFormaNoninterestIncome_f744a5ad-26d1-4902-93f4-672f1cfaa4f2" xlink:href="rnst-20250930.xsd#rnst_BusinessAcquisitionProFormaNoninterestIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:to="loc_rnst_BusinessAcquisitionProFormaNoninterestIncome_f744a5ad-26d1-4902-93f4-672f1cfaa4f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_BusinessAcquisitionProFormaNoninterestExpense_faaba3a0-3dac-4e63-a8bc-cec383269ed2" xlink:href="rnst-20250930.xsd#rnst_BusinessAcquisitionProFormaNoninterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:to="loc_rnst_BusinessAcquisitionProFormaNoninterestExpense_faaba3a0-3dac-4e63-a8bc-cec383269ed2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_9c752fbb-517e-4ad0-a740-05681021e383" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_9c752fbb-517e-4ad0-a740-05681021e383" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_1f886d0f-4532-4e9c-906c-fa85fb38d7e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_3f1a3201-87e5-4238-9746-f5c271757f30" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_1f886d0f-4532-4e9c-906c-fa85fb38d7e1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_a4eb7837-45c1-4006-9297-7f11b33a7bc5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_1f886d0f-4532-4e9c-906c-fa85fb38d7e1" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_a4eb7837-45c1-4006-9297-7f11b33a7bc5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_4b62ff62-4d7e-4185-a1ac-cf1e33cbe5ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_1f886d0f-4532-4e9c-906c-fa85fb38d7e1" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_4b62ff62-4d7e-4185-a1ac-cf1e33cbe5ad" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SecuritiesAmortizedCostandFairValueofSecuritiesAvailableforSaleDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SecuritiesAmortizedCostandFairValueofSecuritiesAvailableforSaleDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SecuritiesAmortizedCostandFairValueofSecuritiesAvailableforSaleDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_8465668f-2b2b-4be2-b2c3-c1869e967254" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_b0aae697-6eab-4535-bf49-145a2e6da668" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_8465668f-2b2b-4be2-b2c3-c1869e967254" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_b0aae697-6eab-4535-bf49-145a2e6da668" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_cd9abef2-f281-4cd6-9893-184eb46fd56c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_b0aae697-6eab-4535-bf49-145a2e6da668" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_cd9abef2-f281-4cd6-9893-184eb46fd56c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_cd9abef2-f281-4cd6-9893-184eb46fd56c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_cd9abef2-f281-4cd6-9893-184eb46fd56c" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_cd9abef2-f281-4cd6-9893-184eb46fd56c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_88bd3f1d-b153-4662-ac74-b99a73b5cb93" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_cd9abef2-f281-4cd6-9893-184eb46fd56c" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_88bd3f1d-b153-4662-ac74-b99a73b5cb93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_c55d5d41-0cdf-4121-8696-dce05c9b1286" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_88bd3f1d-b153-4662-ac74-b99a73b5cb93" xlink:to="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_c55d5d41-0cdf-4121-8696-dce05c9b1286" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_f8abb0e6-6edf-4b44-ac22-9c4c385dd815" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyCollateralizedMortgageObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_88bd3f1d-b153-4662-ac74-b99a73b5cb93" xlink:to="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_f8abb0e6-6edf-4b44-ac22-9c4c385dd815" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_69f1e0f9-0a20-4d81-b8e9-1e383130db76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_b0aae697-6eab-4535-bf49-145a2e6da668" xlink:to="loc_us-gaap_FinancialInstrumentAxis_69f1e0f9-0a20-4d81-b8e9-1e383130db76" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_69f1e0f9-0a20-4d81-b8e9-1e383130db76_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_69f1e0f9-0a20-4d81-b8e9-1e383130db76" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_69f1e0f9-0a20-4d81-b8e9-1e383130db76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_08e02df7-d434-4ebb-bc3b-9c9e66a9ff11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_69f1e0f9-0a20-4d81-b8e9-1e383130db76" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_08e02df7-d434-4ebb-bc3b-9c9e66a9ff11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_e34e4107-d955-4ad5-89dc-91b193d3eba6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_08e02df7-d434-4ebb-bc3b-9c9e66a9ff11" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_e34e4107-d955-4ad5-89dc-91b193d3eba6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_1afcaa2c-6ba3-44a3-baf1-c7374270960b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_08e02df7-d434-4ebb-bc3b-9c9e66a9ff11" xlink:to="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_1afcaa2c-6ba3-44a3-baf1-c7374270960b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_d14156cf-f7f3-45da-a08b-019728084573" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_08e02df7-d434-4ebb-bc3b-9c9e66a9ff11" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_d14156cf-f7f3-45da-a08b-019728084573" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_5f50dc15-b2fa-40e4-a7a9-b3fec77d6e6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_08e02df7-d434-4ebb-bc3b-9c9e66a9ff11" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_5f50dc15-b2fa-40e4-a7a9-b3fec77d6e6e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_b49dbf59-1ce9-44a5-85bf-4110e2449e79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_8465668f-2b2b-4be2-b2c3-c1869e967254" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_b49dbf59-1ce9-44a5-85bf-4110e2449e79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_d1ffdc29-8865-44a1-bc7b-1fdd55147041" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_b49dbf59-1ce9-44a5-85bf-4110e2449e79" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_d1ffdc29-8865-44a1-bc7b-1fdd55147041" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_925a15df-5e96-41df-a523-3ffd26d270f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_b49dbf59-1ce9-44a5-85bf-4110e2449e79" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_925a15df-5e96-41df-a523-3ffd26d270f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_9b809c16-ac2e-4055-9e46-90b6e2927e5d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_b49dbf59-1ce9-44a5-85bf-4110e2449e79" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_9b809c16-ac2e-4055-9e46-90b6e2927e5d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_8ec05ddd-bd2d-4894-80b6-78dee9f5b406" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_b49dbf59-1ce9-44a5-85bf-4110e2449e79" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_8ec05ddd-bd2d-4894-80b6-78dee9f5b406" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SecuritiesAmortizedCostandFairValueHeldtoMaturityDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SecuritiesAmortizedCostandFairValueHeldtoMaturityDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SecuritiesAmortizedCostandFairValueHeldtoMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesTable_cbdf2504-599d-460f-b9aa-42aefedd3957" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfHeldToMaturitySecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesTable_cbdf2504-599d-460f-b9aa-42aefedd3957" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_813507ce-b32c-4e2f-96e5-a53811623341" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesTable_cbdf2504-599d-460f-b9aa-42aefedd3957" xlink:to="loc_us-gaap_FinancialInstrumentAxis_813507ce-b32c-4e2f-96e5-a53811623341" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_813507ce-b32c-4e2f-96e5-a53811623341_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_813507ce-b32c-4e2f-96e5-a53811623341" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_813507ce-b32c-4e2f-96e5-a53811623341_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0c0c7eae-260b-4608-b1a1-43f04a2fceed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_813507ce-b32c-4e2f-96e5-a53811623341" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0c0c7eae-260b-4608-b1a1-43f04a2fceed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_6d1e6a17-69df-427b-aacd-3ac63172cb56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0c0c7eae-260b-4608-b1a1-43f04a2fceed" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_6d1e6a17-69df-427b-aacd-3ac63172cb56" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_bfac66b8-c43f-4146-a882-0b775e45d4cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0c0c7eae-260b-4608-b1a1-43f04a2fceed" xlink:to="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_bfac66b8-c43f-4146-a882-0b775e45d4cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_03ef22aa-82a1-4b3c-b092-9daf1bd9150e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0c0c7eae-260b-4608-b1a1-43f04a2fceed" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_03ef22aa-82a1-4b3c-b092-9daf1bd9150e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_67fec269-9c4c-4e4a-9086-5a30b3f65f31" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0c0c7eae-260b-4608-b1a1-43f04a2fceed" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_67fec269-9c4c-4e4a-9086-5a30b3f65f31" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_f514b372-07f0-4620-a9ae-0430b557bffd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesTable_cbdf2504-599d-460f-b9aa-42aefedd3957" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_f514b372-07f0-4620-a9ae-0430b557bffd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_f514b372-07f0-4620-a9ae-0430b557bffd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_f514b372-07f0-4620-a9ae-0430b557bffd" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_f514b372-07f0-4620-a9ae-0430b557bffd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea102bfb-2a25-4c72-b08a-7402cb22e059" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_f514b372-07f0-4620-a9ae-0430b557bffd" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea102bfb-2a25-4c72-b08a-7402cb22e059" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_455b6464-0c76-4d90-93ef-1b43905389b6" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea102bfb-2a25-4c72-b08a-7402cb22e059" xlink:to="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_455b6464-0c76-4d90-93ef-1b43905389b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_df6f131e-e38c-4560-b6aa-0bd63e2f16c5" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyCollateralizedMortgageObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_ea102bfb-2a25-4c72-b08a-7402cb22e059" xlink:to="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_df6f131e-e38c-4560-b6aa-0bd63e2f16c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecurities_c980eb74-9874-4448-bc5e-16127a230c81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_HeldToMaturitySecurities_c980eb74-9874-4448-bc5e-16127a230c81" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_5b5a9fb0-b623-4c8b-8933-fbd540621eca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_5b5a9fb0-b623-4c8b-8933-fbd540621eca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_181a389f-5313-4c20-aa89-0df56312a391" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_181a389f-5313-4c20-aa89-0df56312a391" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_a189f3a8-05fe-4ac2-b3e5-928ff77d0752" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_a189f3a8-05fe-4ac2-b3e5-928ff77d0752" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss_e522d9c6-40cd-4194-aa0f-5e49954f59e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss_e522d9c6-40cd-4194-aa0f-5e49954f59e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_cb685d13-e384-4104-8f20-f9af595fb880" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfHeldToMaturitySecuritiesLineItems_c12d75b5-1183-4780-bcb5-f6cb60b00b1e" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss_cb685d13-e384-4104-8f20-f9af595fb880" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SecuritiesNarrativeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SecuritiesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SecuritiesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_353165a4-d2ef-4063-bdcb-4ccc7da7ba00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20ee65af-80cb-43d3-8d2b-2a9f7be95183" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_353165a4-d2ef-4063-bdcb-4ccc7da7ba00" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20ee65af-80cb-43d3-8d2b-2a9f7be95183" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_8de95b1f-f0f3-43e9-89cf-1d99f56b5f15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20ee65af-80cb-43d3-8d2b-2a9f7be95183" xlink:to="loc_us-gaap_InvestmentTypeAxis_8de95b1f-f0f3-43e9-89cf-1d99f56b5f15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_8de95b1f-f0f3-43e9-89cf-1d99f56b5f15_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_8de95b1f-f0f3-43e9-89cf-1d99f56b5f15" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_8de95b1f-f0f3-43e9-89cf-1d99f56b5f15_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_7e94025b-0b94-4047-9181-42a04c1e471a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_8de95b1f-f0f3-43e9-89cf-1d99f56b5f15" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_7e94025b-0b94-4047-9181-42a04c1e471a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_SecureGovernmentPublicAndTrustDepositsMember_d8b44424-d8f6-4d97-86f4-a0ab10577824" xlink:href="rnst-20250930.xsd#rnst_SecureGovernmentPublicAndTrustDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_7e94025b-0b94-4047-9181-42a04c1e471a" xlink:to="loc_rnst_SecureGovernmentPublicAndTrustDepositsMember_d8b44424-d8f6-4d97-86f4-a0ab10577824" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtMember_8270584c-14ff-48e9-a6a3-fdbac50a1793" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_7e94025b-0b94-4047-9181-42a04c1e471a" xlink:to="loc_us-gaap_ShortTermDebtMember_8270584c-14ff-48e9-a6a3-fdbac50a1793" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DerivativeInstrumentsMember_6146088f-0e21-4bf3-bb89-e97d86b71e9c" xlink:href="rnst-20250930.xsd#rnst_DerivativeInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_7e94025b-0b94-4047-9181-42a04c1e471a" xlink:to="loc_rnst_DerivativeInstrumentsMember_6146088f-0e21-4bf3-bb89-e97d86b71e9c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_c1e269a2-c48f-4d72-b383-767fbd78bb35" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20ee65af-80cb-43d3-8d2b-2a9f7be95183" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_c1e269a2-c48f-4d72-b383-767fbd78bb35" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c1e269a2-c48f-4d72-b383-767fbd78bb35_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_c1e269a2-c48f-4d72-b383-767fbd78bb35" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c1e269a2-c48f-4d72-b383-767fbd78bb35_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0bf985d-4f41-4d49-b12a-dd549282f1eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_c1e269a2-c48f-4d72-b383-767fbd78bb35" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0bf985d-4f41-4d49-b12a-dd549282f1eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TheFirstFairValueMember_10e11323-f0d4-493e-9736-ccfc7e54b602" xlink:href="rnst-20250930.xsd#rnst_TheFirstFairValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0bf985d-4f41-4d49-b12a-dd549282f1eb" xlink:to="loc_rnst_TheFirstFairValueMember_10e11323-f0d4-493e-9736-ccfc7e54b602" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_49d7b940-a0e8-473f-abe7-8571092d95e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_353165a4-d2ef-4063-bdcb-4ccc7da7ba00" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_49d7b940-a0e8-473f-abe7-8571092d95e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleRestricted_237da653-3f86-4a8e-8bda-1b59c5408570" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleRestricted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_353165a4-d2ef-4063-bdcb-4ccc7da7ba00" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleRestricted_237da653-3f86-4a8e-8bda-1b59c5408570" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss_1599b0d6-4073-4eec-8156-506774ddb901" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_353165a4-d2ef-4063-bdcb-4ccc7da7ba00" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss_1599b0d6-4073-4eec-8156-506774ddb901" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SecuritiesSecuritiesSoldDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SecuritiesSecuritiesSoldDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SecuritiesSecuritiesSoldDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_2787933c-859d-466a-8388-859e377a01e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_225d293e-9103-4183-82a0-1fc7d8867555" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_2787933c-859d-466a-8388-859e377a01e6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_225d293e-9103-4183-82a0-1fc7d8867555" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_dc2df37a-6e6e-40f5-8021-8804807c9ac3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_225d293e-9103-4183-82a0-1fc7d8867555" xlink:to="loc_us-gaap_FinancialInstrumentAxis_dc2df37a-6e6e-40f5-8021-8804807c9ac3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_dc2df37a-6e6e-40f5-8021-8804807c9ac3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_dc2df37a-6e6e-40f5-8021-8804807c9ac3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_dc2df37a-6e6e-40f5-8021-8804807c9ac3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_dc2df37a-6e6e-40f5-8021-8804807c9ac3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_787d89d1-341a-499b-9995-aee59bb87322" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:to="loc_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_787d89d1-341a-499b-9995-aee59bb87322" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_574101e5-ba64-4560-9d16-3b0b76c3662d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_574101e5-ba64-4560-9d16-3b0b76c3662d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_5f7651f7-c282-4076-955e-dcb0eedbf5f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:to="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_5f7651f7-c282-4076-955e-dcb0eedbf5f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_deecde2c-b621-4d99-bdd5-0a2d9a537bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_deecde2c-b621-4d99-bdd5-0a2d9a537bf9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_2ab79a0f-fe34-4c9b-b8f1-ab9c7ce9b673" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e5a13a9b-883a-4d47-81bc-1b1e3bcf4ed5" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_2ab79a0f-fe34-4c9b-b8f1-ab9c7ce9b673" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_4d2ddc74-12da-40bf-8c75-3fa6bb841ba5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_225d293e-9103-4183-82a0-1fc7d8867555" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_4d2ddc74-12da-40bf-8c75-3fa6bb841ba5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4d2ddc74-12da-40bf-8c75-3fa6bb841ba5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_4d2ddc74-12da-40bf-8c75-3fa6bb841ba5" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4d2ddc74-12da-40bf-8c75-3fa6bb841ba5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4b431310-a777-47b5-81e6-49409881a47a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_4d2ddc74-12da-40bf-8c75-3fa6bb841ba5" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4b431310-a777-47b5-81e6-49409881a47a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_a76c2c88-fe09-4b7b-b70f-d24c456b0685" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4b431310-a777-47b5-81e6-49409881a47a" xlink:to="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_a76c2c88-fe09-4b7b-b70f-d24c456b0685" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_d36fbf1c-bdba-4eae-9856-792781c3a449" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyCollateralizedMortgageObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4b431310-a777-47b5-81e6-49409881a47a" xlink:to="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_d36fbf1c-bdba-4eae-9856-792781c3a449" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesAvailableforSaleSecuritiesSoldatCarryingValue_7aad70b5-ef9f-4b15-bc73-985b436e4059" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesAvailableforSaleSecuritiesSoldatCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_2787933c-859d-466a-8388-859e377a01e6" xlink:to="loc_rnst_DebtSecuritiesAvailableforSaleSecuritiesSoldatCarryingValue_7aad70b5-ef9f-4b15-bc73-985b436e4059" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_bca8cd32-65d8-4341-a983-32aa185f476f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_2787933c-859d-466a-8388-859e377a01e6" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_bca8cd32-65d8-4341-a983-32aa185f476f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_f4fa42f7-a53d-4d47-a3a1-0df5ad523f8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_2787933c-859d-466a-8388-859e377a01e6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss_f4fa42f7-a53d-4d47-a3a1-0df5ad523f8f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SecuritiesContractualMaturityDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SecuritiesContractualMaturityDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SecuritiesContractualMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_62bc5c9a-e569-4eae-acd2-8c7d409d481b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ff2f1e88-a697-4af9-a7d0-0ae105fa935d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_62bc5c9a-e569-4eae-acd2-8c7d409d481b" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ff2f1e88-a697-4af9-a7d0-0ae105fa935d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_608e3eea-6aa6-48a0-8e71-c3ccb592bfda" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ff2f1e88-a697-4af9-a7d0-0ae105fa935d" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_608e3eea-6aa6-48a0-8e71-c3ccb592bfda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_608e3eea-6aa6-48a0-8e71-c3ccb592bfda_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_608e3eea-6aa6-48a0-8e71-c3ccb592bfda" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_608e3eea-6aa6-48a0-8e71-c3ccb592bfda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_6658869f-d246-4824-96e9-103571e7f53c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_608e3eea-6aa6-48a0-8e71-c3ccb592bfda" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_6658869f-d246-4824-96e9-103571e7f53c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_9d0a2f03-1df6-448c-a47e-c36f33726ca9" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_6658869f-d246-4824-96e9-103571e7f53c" xlink:to="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_9d0a2f03-1df6-448c-a47e-c36f33726ca9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_a84c9393-c83e-44e0-b1bc-4e78355b15a5" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyCollateralizedMortgageObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_6658869f-d246-4824-96e9-103571e7f53c" xlink:to="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_a84c9393-c83e-44e0-b1bc-4e78355b15a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_cd6b9af7-ca75-4e5c-bdfb-f88858a12c50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ff2f1e88-a697-4af9-a7d0-0ae105fa935d" xlink:to="loc_us-gaap_FinancialInstrumentAxis_cd6b9af7-ca75-4e5c-bdfb-f88858a12c50" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cd6b9af7-ca75-4e5c-bdfb-f88858a12c50_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_cd6b9af7-ca75-4e5c-bdfb-f88858a12c50" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_cd6b9af7-ca75-4e5c-bdfb-f88858a12c50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b0ea361d-1704-461a-9c4b-aa77386f6ca6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_cd6b9af7-ca75-4e5c-bdfb-f88858a12c50" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b0ea361d-1704-461a-9c4b-aa77386f6ca6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_f9389b83-2888-43cc-9de0-effa78d1d1bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b0ea361d-1704-461a-9c4b-aa77386f6ca6" xlink:to="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_f9389b83-2888-43cc-9de0-effa78d1d1bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_aa3a2513-7977-4e4d-a75f-e7544e64b7b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b0ea361d-1704-461a-9c4b-aa77386f6ca6" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_aa3a2513-7977-4e4d-a75f-e7544e64b7b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_567d63f1-cfc2-43b2-a1b5-15257d990a78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_b0ea361d-1704-461a-9c4b-aa77386f6ca6" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_567d63f1-cfc2-43b2-a1b5-15257d990a78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_SecuritiesDebtMaturitiesAbstract_d36636e2-b7f6-4b3f-95b0-9ee9292669a2" xlink:href="rnst-20250930.xsd#rnst_SecuritiesDebtMaturitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_62bc5c9a-e569-4eae-acd2-8c7d409d481b" xlink:to="loc_rnst_SecuritiesDebtMaturitiesAbstract_d36636e2-b7f6-4b3f-95b0-9ee9292669a2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAbstract_167b13b3-b9a5-4559-8dc6-16bdd5582c80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_SecuritiesDebtMaturitiesAbstract_d36636e2-b7f6-4b3f-95b0-9ee9292669a2" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAbstract_167b13b3-b9a5-4559-8dc6-16bdd5582c80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesClassifiedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAbstract_167b13b3-b9a5-4559-8dc6-16bdd5582c80" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateYearOne_3d78cf8a-bdd5-4097-bfef-5e3733527e50" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateYearOne"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:to="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateYearOne_3d78cf8a-bdd5-4097-bfef-5e3733527e50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive_f773f11a-0390-4372-a286-c8f0898afa96" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:to="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive_f773f11a-0390-4372-a286-c8f0898afa96" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear5Through10_5cfe69b0-5aa0-48ac-b9f8-ddd563a42570" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear5Through10"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:to="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear5Through10_5cfe69b0-5aa0-48ac-b9f8-ddd563a42570" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10_bc21af01-21d3-4ca0-a7c5-b4a697e80fb2" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:to="loc_rnst_DebtSecuritiesHeldToMaturityAmortizedCostBeforeAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10_bc21af01-21d3-4ca0-a7c5-b4a697e80fb2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost_f54e5e31-2bd3-468d-b966-4f1b6e95f671" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:to="loc_rnst_DebtSecuritiesHeldToMaturityMaturityWithoutSingleMaturityDateAmortizedCost_f54e5e31-2bd3-468d-b966-4f1b6e95f671" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecurities_8f7fcfcd-9593-4577-b56b-66a36e039e55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesClassifiedAbstract_989d1705-5576-4527-bf83-3dad35f2c415" xlink:to="loc_us-gaap_HeldToMaturitySecurities_8f7fcfcd-9593-4577-b56b-66a36e039e55" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAbstract_167b13b3-b9a5-4559-8dc6-16bdd5582c80" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue_90af219c-1c49-4c52-bd61-920be658479a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue_90af219c-1c49-4c52-bd61-920be658479a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_483714e5-da5a-4196-9d81-c78a8cfcd4eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_483714e5-da5a-4196-9d81-c78a8cfcd4eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_64221c46-72a4-471d-97a0-36777d59a06e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_64221c46-72a4-471d-97a0-36777d59a06e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue_ae3aabc6-6fe3-4514-a65a-60914e51ccdb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue_ae3aabc6-6fe3-4514-a65a-60914e51ccdb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_9ad33cce-02e0-458c-b9b8-899420fb6ab2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_9ad33cce-02e0-458c-b9b8-899420fb6ab2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_1f8b6814-9479-49e3-b0fb-4e26296e80ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract_18c1181a-ef7d-4322-a7ad-05d9b28f161f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_1f8b6814-9479-49e3-b0fb-4e26296e80ec" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_eb82d25d-fa9c-4658-b657-85233f4d6fdf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_SecuritiesDebtMaturitiesAbstract_d36636e2-b7f6-4b3f-95b0-9ee9292669a2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_eb82d25d-fa9c-4658-b657-85233f4d6fdf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_eb82d25d-fa9c-4658-b657-85233f4d6fdf" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_129949ad-4f4d-429a-b4cc-bf0f5c277ebe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_129949ad-4f4d-429a-b4cc-bf0f5c277ebe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_08802256-9c63-4c87-a743-35b442c078fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_08802256-9c63-4c87-a743-35b442c078fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_07978a17-13e9-4b55-a029-f8cf79161e82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_07978a17-13e9-4b55-a029-f8cf79161e82" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_1c19cd84-d990-494c-bc81-805035177511" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_1c19cd84-d990-494c-bc81-805035177511" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_4118fb1e-cdd7-4370-9f7f-ce10ce35b0c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_4118fb1e-cdd7-4370-9f7f-ce10ce35b0c6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_a7ee6047-0655-4691-a3ac-f9ba8b9ac7ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract_33cadf41-1a21-41c7-89da-e85a1a96c21c" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_a7ee6047-0655-4691-a3ac-f9ba8b9ac7ed" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_eb82d25d-fa9c-4658-b657-85233f4d6fdf" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_f08311df-9725-4eba-9a84-6f01cf545961" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_f08311df-9725-4eba-9a84-6f01cf545961" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_b6c19eaf-aa36-4286-9c52-fc5e81e5c5a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_b6c19eaf-aa36-4286-9c52-fc5e81e5c5a6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_b15684db-57df-47b6-8412-78b7034cff97" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_b15684db-57df-47b6-8412-78b7034cff97" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_13fd7b73-17a2-4a9a-8d56-857bb415c826" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_13fd7b73-17a2-4a9a-8d56-857bb415c826" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_6e9d1a5d-cfb6-4c2f-be75-2329101b1284" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_6e9d1a5d-cfb6-4c2f-be75-2329101b1284" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_81279b9a-ba61-4093-9be4-abb8591e6a0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_05d69452-b47d-43d4-9561-e74a7ad110a9" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_81279b9a-ba61-4093-9be4-abb8591e6a0a" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SecuritiesGrossUnrealizedLossesandFairValuebyInvestmentCategoryDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SecuritiesGrossUnrealizedLossesandFairValuebyInvestmentCategoryDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SecuritiesGrossUnrealizedLossesandFairValuebyInvestmentCategoryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_816b87e1-4a2f-458c-ab58-ba84bda3d16f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ec54d039-781e-4c52-81ca-743146ceee54" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_816b87e1-4a2f-458c-ab58-ba84bda3d16f" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ec54d039-781e-4c52-81ca-743146ceee54" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_eea9e6ce-ff06-4c51-ac5e-ea3892673f47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ec54d039-781e-4c52-81ca-743146ceee54" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_eea9e6ce-ff06-4c51-ac5e-ea3892673f47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_eea9e6ce-ff06-4c51-ac5e-ea3892673f47_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_eea9e6ce-ff06-4c51-ac5e-ea3892673f47" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_eea9e6ce-ff06-4c51-ac5e-ea3892673f47_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_335e32af-16fa-4404-bef9-7dd69899d77d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_eea9e6ce-ff06-4c51-ac5e-ea3892673f47" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_335e32af-16fa-4404-bef9-7dd69899d77d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_ff105843-c06b-44e3-bd05-d6550bb36533" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_335e32af-16fa-4404-bef9-7dd69899d77d" xlink:to="loc_rnst_GovernmentAgencyMortgageBackedSecuritiesMember_ff105843-c06b-44e3-bd05-d6550bb36533" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_f26b8cfa-1d65-40f3-8764-6fc7820b4d24" xlink:href="rnst-20250930.xsd#rnst_GovernmentAgencyCollateralizedMortgageObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_335e32af-16fa-4404-bef9-7dd69899d77d" xlink:to="loc_rnst_GovernmentAgencyCollateralizedMortgageObligationsMember_f26b8cfa-1d65-40f3-8764-6fc7820b4d24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_0d51b204-5f29-400f-8167-01153eefdfa0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_ec54d039-781e-4c52-81ca-743146ceee54" xlink:to="loc_us-gaap_FinancialInstrumentAxis_0d51b204-5f29-400f-8167-01153eefdfa0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0d51b204-5f29-400f-8167-01153eefdfa0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_0d51b204-5f29-400f-8167-01153eefdfa0" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0d51b204-5f29-400f-8167-01153eefdfa0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e7cc3a12-62f8-4c63-ad34-0d0ad629cfde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_0d51b204-5f29-400f-8167-01153eefdfa0" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e7cc3a12-62f8-4c63-ad34-0d0ad629cfde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_bd6a0ce5-207a-44f6-9bcb-3fdfea4b4cea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e7cc3a12-62f8-4c63-ad34-0d0ad629cfde" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_bd6a0ce5-207a-44f6-9bcb-3fdfea4b4cea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_5cf5d66a-f4a9-4ea7-b0c5-fb6aa0fe84eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e7cc3a12-62f8-4c63-ad34-0d0ad629cfde" xlink:to="loc_us-gaap_ResidentialMortgageBackedSecuritiesMember_5cf5d66a-f4a9-4ea7-b0c5-fb6aa0fe84eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_d6e26c9d-1532-4ee0-9b72-8c16fc576f8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e7cc3a12-62f8-4c63-ad34-0d0ad629cfde" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_d6e26c9d-1532-4ee0-9b72-8c16fc576f8f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_829edb2f-779d-4a86-a478-fe7900c3709e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e7cc3a12-62f8-4c63-ad34-0d0ad629cfde" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_829edb2f-779d-4a86-a478-fe7900c3709e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract_0302e73d-f69d-4ecb-97a6-fe63c64ea6a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_816b87e1-4a2f-458c-ab58-ba84bda3d16f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract_0302e73d-f69d-4ecb-97a6-fe63c64ea6a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract_0302e73d-f69d-4ecb-97a6-fe63c64ea6a8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_46b32f29-528b-425d-a8da-dedbef3395a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_46b32f29-528b-425d-a8da-dedbef3395a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_1fbd769d-47e5-43ea-9d85-5ec73e310d76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_1fbd769d-47e5-43ea-9d85-5ec73e310d76" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_aabbde92-d7af-48bb-8697-0d793a8b56fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_aabbde92-d7af-48bb-8697-0d793a8b56fa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_1607a5c9-8914-4a4a-acd8-fa0d99f77fc4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_1607a5c9-8914-4a4a-acd8-fa0d99f77fc4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_9ef56458-7047-4c84-8e5e-98a18f3cc0a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_9ef56458-7047-4c84-8e5e-98a18f3cc0a0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_0fa4a319-8231-447a-b277-f89e6e4434a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_0fa4a319-8231-447a-b277-f89e6e4434a3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_bb0013b1-372b-4748-af4a-e48cf7371d1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_bb0013b1-372b-4748-af4a-e48cf7371d1e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_55c7a9a1-ed0b-47f0-8baa-75f4abf56966" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_55c7a9a1-ed0b-47f0-8baa-75f4abf56966" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_74f1cbd5-2062-46c4-a935-43712e64fda7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_2e1bdf54-62d9-46f8-80a3-885591bc1a16" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_74f1cbd5-2062-46c4-a935-43712e64fda7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAbstract_0302e73d-f69d-4ecb-97a6-fe63c64ea6a8" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldForMaturityContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_0447ffe3-78ec-4b7a-930e-1b9d2fb07a16" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldForMaturityContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_rnst_DebtSecuritiesHeldForMaturityContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_0447ffe3-78ec-4b7a-930e-1b9d2fb07a16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_8a5b4102-c3d2-4dd8-8f2e-5cc88d73764e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_8a5b4102-c3d2-4dd8-8f2e-5cc88d73764e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_e9a9403b-98a8-41c6-9d6c-3c8092d8944d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_e9a9403b-98a8-41c6-9d6c-3c8092d8944d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldForMaturityContinuousUnrealizedLossPosition12MonthsOrMoreNumberOfPositions_282fcc79-7889-40f9-8022-9d6036798bf6" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldForMaturityContinuousUnrealizedLossPosition12MonthsOrMoreNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_rnst_DebtSecuritiesHeldForMaturityContinuousUnrealizedLossPosition12MonthsOrMoreNumberOfPositions_282fcc79-7889-40f9-8022-9d6036798bf6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_28f4a600-3664-4c2d-93e4-576b122fb154" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_28f4a600-3664-4c2d-93e4-576b122fb154" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_034712f2-fa44-49b3-a6f9-611221ccbdfd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_034712f2-fa44-49b3-a6f9-611221ccbdfd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesHeldForMaturityUnrealizedLossPositionNumberOfPositions_ab69726e-542b-45fd-8506-f8c1ccf3bde2" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesHeldForMaturityUnrealizedLossPositionNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_rnst_DebtSecuritiesHeldForMaturityUnrealizedLossPositionNumberOfPositions_ab69726e-542b-45fd-8506-f8c1ccf3bde2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue_4e46227e-a529-443e-b1b7-fccfc879388e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue_4e46227e-a529-443e-b1b7-fccfc879388e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_cd9b2de2-69a0-4161-b37d-5f5bfa4e07a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract_7ced42d5-720f-48b2-a847-395f8078daa4" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_cd9b2de2-69a0-4161-b37d-5f5bfa4e07a6" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/LoansScheduleofNonPurchasedLoansandLeasesDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#LoansScheduleofNonPurchasedLoansandLeasesDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/LoansScheduleofNonPurchasedLoansandLeasesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_2afb78c8-afe8-444a-a3dc-f39d6f163fea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_54bce6ad-963d-4c98-80aa-7c952ec8a516" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_2afb78c8-afe8-444a-a3dc-f39d6f163fea" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_54bce6ad-963d-4c98-80aa-7c952ec8a516" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_bbb45d0e-627b-4805-b85e-c3f2b54b36c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_54bce6ad-963d-4c98-80aa-7c952ec8a516" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_bbb45d0e-627b-4805-b85e-c3f2b54b36c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_bbb45d0e-627b-4805-b85e-c3f2b54b36c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_bbb45d0e-627b-4805-b85e-c3f2b54b36c7" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_bbb45d0e-627b-4805-b85e-c3f2b54b36c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_bbb45d0e-627b-4805-b85e-c3f2b54b36c7" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialLoanMember_34b24858-d570-40b5-bf99-aa5e2617229a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:to="loc_us-gaap_CommercialLoanMember_34b24858-d570-40b5-bf99-aa5e2617229a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LeaseFinancingMember_0b06668b-ce14-4c28-bc62-216eb4653c63" xlink:href="rnst-20250930.xsd#rnst_LeaseFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:to="loc_rnst_LeaseFinancingMember_0b06668b-ce14-4c28-bc62-216eb4653c63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember_5d9ef3d2-06a7-4308-982e-dea6e640c393" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:to="loc_us-gaap_ConstructionLoansMember_5d9ef3d2-06a7-4308-982e-dea6e640c393" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RealEstateOneToFourFamilyMortgageMember_2a53b39e-b1e6-4d57-a82c-c89d6be67efa" xlink:href="rnst-20250930.xsd#rnst_RealEstateOneToFourFamilyMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:to="loc_rnst_RealEstateOneToFourFamilyMortgageMember_2a53b39e-b1e6-4d57-a82c-c89d6be67efa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialResidentialMortgageMember_a27f2937-f4b5-4338-8952-cf654d11164b" xlink:href="rnst-20250930.xsd#rnst_CommercialResidentialMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:to="loc_rnst_CommercialResidentialMortgageMember_a27f2937-f4b5-4338-8952-cf654d11164b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InstallmentLoansToIndividualsMember_4c06bbb4-68d7-4f20-bb8d-1911fa478a4e" xlink:href="rnst-20250930.xsd#rnst_InstallmentLoansToIndividualsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_2ed43b3e-8c8f-4a57-91b5-2b37ae91b888" xlink:to="loc_rnst_InstallmentLoansToIndividualsMember_4c06bbb4-68d7-4f20-bb8d-1911fa478a4e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_1bedd7fa-52f7-401e-9f20-d1d2911b358b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_54bce6ad-963d-4c98-80aa-7c952ec8a516" xlink:to="loc_us-gaap_CollateralAxis_1bedd7fa-52f7-401e-9f20-d1d2911b358b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_1bedd7fa-52f7-401e-9f20-d1d2911b358b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_1bedd7fa-52f7-401e-9f20-d1d2911b358b" xlink:to="loc_us-gaap_CollateralDomain_1bedd7fa-52f7-401e-9f20-d1d2911b358b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_1956197d-c993-4a17-9844-a1ffc2b5e216" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_1bedd7fa-52f7-401e-9f20-d1d2911b358b" xlink:to="loc_us-gaap_CollateralDomain_1956197d-c993-4a17-9844-a1ffc2b5e216" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_58c6fe3a-4ccd-46b5-81de-0c36e6a30dbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_1956197d-c993-4a17-9844-a1ffc2b5e216" xlink:to="loc_us-gaap_ResidentialRealEstateMember_58c6fe3a-4ccd-46b5-81de-0c36e6a30dbd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_f325fc36-9f9f-4dde-827f-8ad8422456dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_1956197d-c993-4a17-9844-a1ffc2b5e216" xlink:to="loc_us-gaap_CommercialRealEstateMember_f325fc36-9f9f-4dde-827f-8ad8422456dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoansAxis_bdcc09e7-7101-4796-8377-84cc58c9bd9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoansAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_54bce6ad-963d-4c98-80aa-7c952ec8a516" xlink:to="loc_us-gaap_ParticipatingMortgageLoansAxis_bdcc09e7-7101-4796-8377-84cc58c9bd9c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_bdcc09e7-7101-4796-8377-84cc58c9bd9c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_bdcc09e7-7101-4796-8377-84cc58c9bd9c" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_bdcc09e7-7101-4796-8377-84cc58c9bd9c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_bdcc09e7-7101-4796-8377-84cc58c9bd9c" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PrimaryMember_d100ebf3-0c99-4312-a40c-a5f804b327ba" xlink:href="rnst-20250930.xsd#rnst_PrimaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_rnst_PrimaryMember_d100ebf3-0c99-4312-a40c-a5f804b327ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HomeEquityLoanMember_e8aa5167-7599-4cc8-b857-068288aa6075" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HomeEquityLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_us-gaap_HomeEquityLoanMember_e8aa5167-7599-4cc8-b857-068288aa6075" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RentalInvestmentMember_76b6ea82-85a5-4f7f-9e83-86f748d8421e" xlink:href="rnst-20250930.xsd#rnst_RentalInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_rnst_RentalInvestmentMember_76b6ea82-85a5-4f7f-9e83-86f748d8421e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialLandDevelopmentMember_ea7c5575-12db-4141-9216-5267ee5d7ba8" xlink:href="rnst-20250930.xsd#rnst_CommercialLandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_rnst_CommercialLandDevelopmentMember_ea7c5575-12db-4141-9216-5267ee5d7ba8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OwnerOccupiedMember_7ea0b02c-ffa3-42c8-9ac9-7c833a13480c" xlink:href="rnst-20250930.xsd#rnst_OwnerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_rnst_OwnerOccupiedMember_7ea0b02c-ffa3-42c8-9ac9-7c833a13480c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NonownerOccupiedMember_2eb946b8-a761-415e-8f1e-145229fc11b8" xlink:href="rnst-20250930.xsd#rnst_NonownerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_rnst_NonownerOccupiedMember_2eb946b8-a761-415e-8f1e-145229fc11b8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LandDevelopmentMember_26db3ee7-662c-40b1-b096-eabaede3646e" xlink:href="rnst-20250930.xsd#rnst_LandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_76e0e40d-50d7-4cf9-9489-c8a54bd27bbe" xlink:to="loc_rnst_LandDevelopmentMember_26db3ee7-662c-40b1-b096-eabaede3646e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract_2b7ff7f7-2eb8-47cf-86c8-01abac965a14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_2afb78c8-afe8-444a-a3dc-f39d6f163fea" xlink:to="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract_2b7ff7f7-2eb8-47cf-86c8-01abac965a14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess_386dee55-118c-4e88-8f26-2ac6bbea567b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract_2b7ff7f7-2eb8-47cf-86c8-01abac965a14" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess_386dee55-118c-4e88-8f26-2ac6bbea567b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount_d9647ac2-dc55-4ef6-a02a-8d14894ba1ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract_2b7ff7f7-2eb8-47cf-86c8-01abac965a14" xlink:to="loc_us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount_d9647ac2-dc55-4ef6-a02a-8d14894ba1ec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_2d648360-fa97-4b46-84e4-5a7dd1ea000e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract_2b7ff7f7-2eb8-47cf-86c8-01abac965a14" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_2d648360-fa97-4b46-84e4-5a7dd1ea000e" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/LoansNarrativeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#LoansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/LoansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_2cd10167-5e03-4380-afca-c9eaddafa502" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_2cd10167-5e03-4380-afca-c9eaddafa502" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_f2260b0f-1a80-4b84-a129-e24becbb5f04" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_2cd10167-5e03-4380-afca-c9eaddafa502" xlink:to="loc_srt_RangeAxis_f2260b0f-1a80-4b84-a129-e24becbb5f04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f2260b0f-1a80-4b84-a129-e24becbb5f04_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_f2260b0f-1a80-4b84-a129-e24becbb5f04" xlink:to="loc_srt_RangeMember_f2260b0f-1a80-4b84-a129-e24becbb5f04_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f995d473-7c36-44da-86e4-df798b17cd1c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_f2260b0f-1a80-4b84-a129-e24becbb5f04" xlink:to="loc_srt_RangeMember_f995d473-7c36-44da-86e4-df798b17cd1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_4cd4f2ed-4ec7-48d9-89b4-d7f380df3be9" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f995d473-7c36-44da-86e4-df798b17cd1c" xlink:to="loc_srt_MinimumMember_4cd4f2ed-4ec7-48d9-89b4-d7f380df3be9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_db454b71-f5c7-44f6-b741-f98eff4633e1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f995d473-7c36-44da-86e4-df798b17cd1c" xlink:to="loc_srt_MaximumMember_db454b71-f5c7-44f6-b741-f98eff4633e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_a51d29fa-fafc-4b4e-861f-4766bc3be1b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_2cd10167-5e03-4380-afca-c9eaddafa502" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_a51d29fa-fafc-4b4e-861f-4766bc3be1b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_a51d29fa-fafc-4b4e-861f-4766bc3be1b3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_a51d29fa-fafc-4b4e-861f-4766bc3be1b3" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_a51d29fa-fafc-4b4e-861f-4766bc3be1b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_8934ad3e-90b8-40c5-858e-b5077cf7bdfb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_a51d29fa-fafc-4b4e-861f-4766bc3be1b3" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_8934ad3e-90b8-40c5-858e-b5077cf7bdfb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalInvestmentGradeMember_82ffc107-a7c5-47e0-ad67-b9640f43f43a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalInvestmentGradeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_8934ad3e-90b8-40c5-858e-b5077cf7bdfb" xlink:to="loc_us-gaap_InternalInvestmentGradeMember_82ffc107-a7c5-47e0-ad67-b9640f43f43a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PassMember_16d8d94e-9192-4171-9f46-23d60cd0c951" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PassMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_8934ad3e-90b8-40c5-858e-b5077cf7bdfb" xlink:to="loc_us-gaap_PassMember_16d8d94e-9192-4171-9f46-23d60cd0c951" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SpecialMentionMember_a23f4072-587d-4c52-bb8e-f76bdb6b1680" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SpecialMentionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_8934ad3e-90b8-40c5-858e-b5077cf7bdfb" xlink:to="loc_us-gaap_SpecialMentionMember_a23f4072-587d-4c52-bb8e-f76bdb6b1680" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_MortgageAndCommercialLoansDiscontinuedPastDuePeriod_567a339a-f7e6-49db-8d21-4795cf888ab6" xlink:href="rnst-20250930.xsd#rnst_MortgageAndCommercialLoansDiscontinuedPastDuePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_rnst_MortgageAndCommercialLoansDiscontinuedPastDuePeriod_567a339a-f7e6-49db-8d21-4795cf888ab6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ConsumerAndOtherRetailLoansChargedOffPastDuePeriod_8c560c1e-a8c8-4a89-997f-197d67022ff6" xlink:href="rnst-20250930.xsd#rnst_ConsumerAndOtherRetailLoansChargedOffPastDuePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_rnst_ConsumerAndOtherRetailLoansChargedOffPastDuePeriod_8c560c1e-a8c8-4a89-997f-197d67022ff6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment_38e7083a-42ac-4903-896d-b1ab405b4cc6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment_38e7083a-42ac-4903-896d-b1ab405b4cc6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1_bb192b2c-7f6f-4a8f-9bbc-7063befbda26" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1_bb192b2c-7f6f-4a8f-9bbc-7063befbda26" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnusedCommitmentsToExtendCredit_19e824f8-7310-4785-aba8-233bafcfe2cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnusedCommitmentsToExtendCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_us-gaap_UnusedCommitmentsToExtendCredit_19e824f8-7310-4785-aba8-233bafcfe2cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FinancingReceivableInternalRiskRatingGrade_6e59c7d2-42b2-4e74-97e9-ec6907c5b036" xlink:href="rnst-20250930.xsd#rnst_FinancingReceivableInternalRiskRatingGrade"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_252cfa07-65b4-4138-868a-03d9a7909ccd" xlink:to="loc_rnst_FinancingReceivableInternalRiskRatingGrade_6e59c7d2-42b2-4e74-97e9-ec6907c5b036" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/LoansAgingofPastDueandNonaccrualLoansDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#LoansAgingofPastDueandNonaccrualLoansDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/LoansAgingofPastDueandNonaccrualLoansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_f49b6603-f63d-40d7-91c3-53df26a94e72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_f49b6603-f63d-40d7-91c3-53df26a94e72" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a31efe05-8bae-4433-a599-893506fd7239" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a31efe05-8bae-4433-a599-893506fd7239" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_a31efe05-8bae-4433-a599-893506fd7239_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a31efe05-8bae-4433-a599-893506fd7239" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_a31efe05-8bae-4433-a599-893506fd7239_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a31efe05-8bae-4433-a599-893506fd7239" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialLoanMember_85059359-0577-4094-8a15-de3546bb8951" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:to="loc_us-gaap_CommercialLoanMember_85059359-0577-4094-8a15-de3546bb8951" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LeaseFinancingMember_fc1c99d1-2ed5-4601-95d7-7fb7d7381e99" xlink:href="rnst-20250930.xsd#rnst_LeaseFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:to="loc_rnst_LeaseFinancingMember_fc1c99d1-2ed5-4601-95d7-7fb7d7381e99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember_42bc42a8-7ec5-4520-aab7-bacec55ff09b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:to="loc_us-gaap_ConstructionLoansMember_42bc42a8-7ec5-4520-aab7-bacec55ff09b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RealEstateOneToFourFamilyMortgageMember_f80b6730-bdf3-4802-b7ad-e6e0233c8253" xlink:href="rnst-20250930.xsd#rnst_RealEstateOneToFourFamilyMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:to="loc_rnst_RealEstateOneToFourFamilyMortgageMember_f80b6730-bdf3-4802-b7ad-e6e0233c8253" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialResidentialMortgageMember_6896ee09-2a7b-4eb1-9cd7-d52b9a564444" xlink:href="rnst-20250930.xsd#rnst_CommercialResidentialMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:to="loc_rnst_CommercialResidentialMortgageMember_6896ee09-2a7b-4eb1-9cd7-d52b9a564444" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InstallmentLoansToIndividualsMember_13a08693-93fc-4588-8d1e-7ce1bcd8b663" xlink:href="rnst-20250930.xsd#rnst_InstallmentLoansToIndividualsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_94cbb615-dd7c-4b9e-be22-0234f33e8a9e" xlink:to="loc_rnst_InstallmentLoansToIndividualsMember_13a08693-93fc-4588-8d1e-7ce1bcd8b663" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_a08c57dc-d0d9-4e48-83fc-887ed2156921" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:to="loc_us-gaap_CollateralAxis_a08c57dc-d0d9-4e48-83fc-887ed2156921" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_a08c57dc-d0d9-4e48-83fc-887ed2156921_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_a08c57dc-d0d9-4e48-83fc-887ed2156921" xlink:to="loc_us-gaap_CollateralDomain_a08c57dc-d0d9-4e48-83fc-887ed2156921_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_d1f05888-4cdd-4885-a429-f1fd01582535" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_a08c57dc-d0d9-4e48-83fc-887ed2156921" xlink:to="loc_us-gaap_CollateralDomain_d1f05888-4cdd-4885-a429-f1fd01582535" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_9c997ff8-fed2-4090-ac96-06d7cdd49f60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_d1f05888-4cdd-4885-a429-f1fd01582535" xlink:to="loc_us-gaap_ResidentialRealEstateMember_9c997ff8-fed2-4090-ac96-06d7cdd49f60" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_e990f808-9089-4f82-8953-e6f862667dfb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_d1f05888-4cdd-4885-a429-f1fd01582535" xlink:to="loc_us-gaap_CommercialRealEstateMember_e990f808-9089-4f82-8953-e6f862667dfb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoansAxis_8e87785a-9276-465e-9160-239f182b402b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoansAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:to="loc_us-gaap_ParticipatingMortgageLoansAxis_8e87785a-9276-465e-9160-239f182b402b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_8e87785a-9276-465e-9160-239f182b402b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_8e87785a-9276-465e-9160-239f182b402b" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_8e87785a-9276-465e-9160-239f182b402b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_8e87785a-9276-465e-9160-239f182b402b" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PrimaryMember_d6fd955a-35ba-4fb0-b1fc-fc1b56ee7716" xlink:href="rnst-20250930.xsd#rnst_PrimaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:to="loc_rnst_PrimaryMember_d6fd955a-35ba-4fb0-b1fc-fc1b56ee7716" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HomeEquityLoanMember_376541b8-39ea-46d1-8fac-200afb5b3723" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HomeEquityLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:to="loc_us-gaap_HomeEquityLoanMember_376541b8-39ea-46d1-8fac-200afb5b3723" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RentalInvestmentMember_b2ec47a5-48e8-42b7-bfed-4bcd120ccecc" xlink:href="rnst-20250930.xsd#rnst_RentalInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:to="loc_rnst_RentalInvestmentMember_b2ec47a5-48e8-42b7-bfed-4bcd120ccecc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LandDevelopmentMember_17c63057-0341-4f20-8b04-ebbbed882a5f" xlink:href="rnst-20250930.xsd#rnst_LandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:to="loc_rnst_LandDevelopmentMember_17c63057-0341-4f20-8b04-ebbbed882a5f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OwnerOccupiedMember_c65b93f3-b125-48ad-8b94-e25303b1a28e" xlink:href="rnst-20250930.xsd#rnst_OwnerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:to="loc_rnst_OwnerOccupiedMember_c65b93f3-b125-48ad-8b94-e25303b1a28e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NonownerOccupiedMember_1ff75a7e-4007-4c2a-8089-77074640df60" xlink:href="rnst-20250930.xsd#rnst_NonownerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7145e1c7-b6e2-416e-a3ca-bef6c573e5e4" xlink:to="loc_rnst_NonownerOccupiedMember_1ff75a7e-4007-4c2a-8089-77074640df60" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_9172ab7e-1c44-4c1a-9963-aca6e108cfb1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_9172ab7e-1c44-4c1a-9963-aca6e108cfb1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_9172ab7e-1c44-4c1a-9963-aca6e108cfb1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_9172ab7e-1c44-4c1a-9963-aca6e108cfb1" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_9172ab7e-1c44-4c1a-9963-aca6e108cfb1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_c3c096f7-5aa2-4228-9707-306eb7916033" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_9172ab7e-1c44-4c1a-9963-aca6e108cfb1" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_c3c096f7-5aa2-4228-9707-306eb7916033" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FinancingReceivables30to89DaysPastDueMember_20c2deb5-1626-4957-ac6f-c5f0d21c7e11" xlink:href="rnst-20250930.xsd#rnst_FinancingReceivables30to89DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_c3c096f7-5aa2-4228-9707-306eb7916033" xlink:to="loc_rnst_FinancingReceivables30to89DaysPastDueMember_20c2deb5-1626-4957-ac6f-c5f0d21c7e11" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_c1f331e0-cc1f-4cb5-b2f2-2038b46e5165" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_c3c096f7-5aa2-4228-9707-306eb7916033" xlink:to="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_c1f331e0-cc1f-4cb5-b2f2-2038b46e5165" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetNotPastDueMember_edb5e87e-a89f-48a3-ad81-efdc539cdb58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialAssetNotPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_c3c096f7-5aa2-4228-9707-306eb7916033" xlink:to="loc_us-gaap_FinancialAssetNotPastDueMember_edb5e87e-a89f-48a3-ad81-efdc539cdb58" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_ca17dfe6-3805-4f09-85c1-2078aadfc2fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_7c60a933-8693-43fa-8c1b-4d474315a0a8" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_ca17dfe6-3805-4f09-85c1-2078aadfc2fc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_ca17dfe6-3805-4f09-85c1-2078aadfc2fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_ca17dfe6-3805-4f09-85c1-2078aadfc2fc" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_ca17dfe6-3805-4f09-85c1-2078aadfc2fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_f4ac3f22-b265-436e-ac94-3bc20f5bfd50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_ca17dfe6-3805-4f09-85c1-2078aadfc2fc" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_f4ac3f22-b265-436e-ac94-3bc20f5bfd50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_AccruingLoansMember_5c043251-22af-4f4a-93c3-df0fbceeba96" xlink:href="rnst-20250930.xsd#rnst_AccruingLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_f4ac3f22-b265-436e-ac94-3bc20f5bfd50" xlink:to="loc_rnst_AccruingLoansMember_5c043251-22af-4f4a-93c3-df0fbceeba96" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NonaccruingLoansMember_ae565408-b83a-478f-9712-a7100bb82c0c" xlink:href="rnst-20250930.xsd#rnst_NonaccruingLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_f4ac3f22-b265-436e-ac94-3bc20f5bfd50" xlink:to="loc_rnst_NonaccruingLoansMember_ae565408-b83a-478f-9712-a7100bb82c0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess_65f6cb2e-06e9-4bdd-8adc-e6cf7d63376f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_f49b6603-f63d-40d7-91c3-53df26a94e72" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess_65f6cb2e-06e9-4bdd-8adc-e6cf7d63376f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcessNet_90b1d8df-4944-4469-8e66-fa5bb11e9f76" xlink:href="rnst-20250930.xsd#rnst_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcessNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_f49b6603-f63d-40d7-91c3-53df26a94e72" xlink:to="loc_rnst_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcessNet_90b1d8df-4944-4469-8e66-fa5bb11e9f76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount_cd3b9277-9770-4d29-9a42-94dadabafab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_f49b6603-f63d-40d7-91c3-53df26a94e72" xlink:to="loc_us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount_cd3b9277-9770-4d29-9a42-94dadabafab4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_4588a917-92f4-45c7-a596-40343b8654ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_f49b6603-f63d-40d7-91c3-53df26a94e72" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_4588a917-92f4-45c7-a596-40343b8654ea" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/LoansScheduleofAmortizedCostBasisofLoanModificationsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#LoansScheduleofAmortizedCostBasisofLoanModificationsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/LoansScheduleofAmortizedCostBasisofLoanModificationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_41052e30-cb7d-40bf-a61a-7adfa82e3959" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ab9d986f-2b50-42f2-beac-eefa309dca3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_41052e30-cb7d-40bf-a61a-7adfa82e3959" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ab9d986f-2b50-42f2-beac-eefa309dca3a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_20e4e37f-bd11-4f0f-bb69-39229723a97b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ab9d986f-2b50-42f2-beac-eefa309dca3a" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_20e4e37f-bd11-4f0f-bb69-39229723a97b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_20e4e37f-bd11-4f0f-bb69-39229723a97b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_20e4e37f-bd11-4f0f-bb69-39229723a97b" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_20e4e37f-bd11-4f0f-bb69-39229723a97b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_20e4e37f-bd11-4f0f-bb69-39229723a97b" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialLoanMember_e3a4cdac-d644-456e-b3ce-5f07691b311a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:to="loc_us-gaap_CommercialLoanMember_e3a4cdac-d644-456e-b3ce-5f07691b311a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LeaseFinancingMember_4b2cd2af-d6f5-4976-aadb-4b05ac576711" xlink:href="rnst-20250930.xsd#rnst_LeaseFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:to="loc_rnst_LeaseFinancingMember_4b2cd2af-d6f5-4976-aadb-4b05ac576711" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember_99078519-44f4-4527-977a-457ca643bea2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:to="loc_us-gaap_ConstructionLoansMember_99078519-44f4-4527-977a-457ca643bea2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RealEstateOneToFourFamilyMortgageMember_83ad89a6-e85e-4bdc-bcde-86e8f16c58be" xlink:href="rnst-20250930.xsd#rnst_RealEstateOneToFourFamilyMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:to="loc_rnst_RealEstateOneToFourFamilyMortgageMember_83ad89a6-e85e-4bdc-bcde-86e8f16c58be" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialResidentialMortgageMember_c0cc5f9d-4af5-412c-8dfd-8e3eb570e744" xlink:href="rnst-20250930.xsd#rnst_CommercialResidentialMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:to="loc_rnst_CommercialResidentialMortgageMember_c0cc5f9d-4af5-412c-8dfd-8e3eb570e744" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InstallmentLoansToIndividualsMember_e3d6a44d-dcf8-4e4c-98b0-a9e00694b8bf" xlink:href="rnst-20250930.xsd#rnst_InstallmentLoansToIndividualsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_7ca6382e-c4c8-4f01-9d89-cade2d84a3c5" xlink:to="loc_rnst_InstallmentLoansToIndividualsMember_e3d6a44d-dcf8-4e4c-98b0-a9e00694b8bf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationAxis_5087df27-57f6-4258-b695-0123e6aad4fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoanRestructuringModificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ab9d986f-2b50-42f2-beac-eefa309dca3a" xlink:to="loc_us-gaap_LoanRestructuringModificationAxis_5087df27-57f6-4258-b695-0123e6aad4fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationDomain_5087df27-57f6-4258-b695-0123e6aad4fd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoanRestructuringModificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LoanRestructuringModificationAxis_5087df27-57f6-4258-b695-0123e6aad4fd" xlink:to="loc_us-gaap_LoanRestructuringModificationDomain_5087df27-57f6-4258-b695-0123e6aad4fd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoanRestructuringModificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LoanRestructuringModificationAxis_5087df27-57f6-4258-b695-0123e6aad4fd" xlink:to="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualInterestRateReductionMember_807d14df-3a38-4c46-a1e7-d88499a06924" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualInterestRateReductionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_us-gaap_ContractualInterestRateReductionMember_807d14df-3a38-4c46-a1e7-d88499a06924" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtendedMaturityMember_66dbd14e-dc19-4f65-90e6-45c4655a0649" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtendedMaturityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_us-gaap_ExtendedMaturityMember_66dbd14e-dc19-4f65-90e6-45c4655a0649" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentDeferralMember_de5c9a12-545e-40b3-82c1-ef85e2412d73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentDeferralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_us-gaap_PaymentDeferralMember_de5c9a12-545e-40b3-82c1-ef85e2412d73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_TermExtensionAndPaymentDelayMember_318a6d87-775e-4ce0-8b95-683a09655ccd" xlink:href="rnst-20250930.xsd#rnst_TermExtensionAndPaymentDelayMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_rnst_TermExtensionAndPaymentDelayMember_318a6d87-775e-4ce0-8b95-683a09655ccd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InterestRateReductionAndTermExtensionMember_00d429a9-b9d4-463a-b058-8936b06fac61" xlink:href="rnst-20250930.xsd#rnst_InterestRateReductionAndTermExtensionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_rnst_InterestRateReductionAndTermExtensionMember_00d429a9-b9d4-463a-b058-8936b06fac61" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InterestRateReductionTermExtensionAndPaymentDelayMember_741de8c3-23ed-4393-9fa4-738330db0d8a" xlink:href="rnst-20250930.xsd#rnst_InterestRateReductionTermExtensionAndPaymentDelayMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_rnst_InterestRateReductionTermExtensionAndPaymentDelayMember_741de8c3-23ed-4393-9fa4-738330db0d8a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InterestRateReductionAndPaymentDelayMember_ce3e3875-8b0d-4023-ae21-5b9edc3563ce" xlink:href="rnst-20250930.xsd#rnst_InterestRateReductionAndPaymentDelayMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_6a6e9ec9-8b95-4fc0-a194-9751d2025033" xlink:to="loc_rnst_InterestRateReductionAndPaymentDelayMember_ce3e3875-8b0d-4023-ae21-5b9edc3563ce" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoansAxis_7ff6be50-3507-4b22-b5ff-c4ec111f11f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoansAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ab9d986f-2b50-42f2-beac-eefa309dca3a" xlink:to="loc_us-gaap_ParticipatingMortgageLoansAxis_7ff6be50-3507-4b22-b5ff-c4ec111f11f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7ff6be50-3507-4b22-b5ff-c4ec111f11f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_7ff6be50-3507-4b22-b5ff-c4ec111f11f6" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_7ff6be50-3507-4b22-b5ff-c4ec111f11f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_7ff6be50-3507-4b22-b5ff-c4ec111f11f6" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_e804203e-72a5-4c59-8920-5d21d16f7fd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_us-gaap_ResidentialRealEstateMember_e804203e-72a5-4c59-8920-5d21d16f7fd5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PrimaryMember_e9ba78bd-d669-45d9-b12e-5e2503521048" xlink:href="rnst-20250930.xsd#rnst_PrimaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_rnst_PrimaryMember_e9ba78bd-d669-45d9-b12e-5e2503521048" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HomeEquityLoanMember_38319e9a-639e-42bc-ab2e-15829c91d3ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HomeEquityLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_us-gaap_HomeEquityLoanMember_38319e9a-639e-42bc-ab2e-15829c91d3ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RentalInvestmentMember_b246e3be-e514-4472-be48-cc56faf8a302" xlink:href="rnst-20250930.xsd#rnst_RentalInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_rnst_RentalInvestmentMember_b246e3be-e514-4472-be48-cc56faf8a302" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OwnerOccupiedMember_58d0dcdf-9952-46ad-a0e2-9517b1f13cc6" xlink:href="rnst-20250930.xsd#rnst_OwnerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_rnst_OwnerOccupiedMember_58d0dcdf-9952-46ad-a0e2-9517b1f13cc6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NonownerOccupiedMember_19964fb4-010c-4ea9-ab1a-aa87a22ead82" xlink:href="rnst-20250930.xsd#rnst_NonownerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_rnst_NonownerOccupiedMember_19964fb4-010c-4ea9-ab1a-aa87a22ead82" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LandDevelopmentMember_309bdde9-e360-43bf-af4f-e951f1ca2024" xlink:href="rnst-20250930.xsd#rnst_LandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_081e504c-718f-417f-b51f-38352ca32577" xlink:to="loc_rnst_LandDevelopmentMember_309bdde9-e360-43bf-af4f-e951f1ca2024" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_d1d1353a-0004-43ca-8350-ac8bee084ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ab9d986f-2b50-42f2-beac-eefa309dca3a" xlink:to="loc_us-gaap_CollateralAxis_d1d1353a-0004-43ca-8350-ac8bee084ca3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_d1d1353a-0004-43ca-8350-ac8bee084ca3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_d1d1353a-0004-43ca-8350-ac8bee084ca3" xlink:to="loc_us-gaap_CollateralDomain_d1d1353a-0004-43ca-8350-ac8bee084ca3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_9db96358-3b29-46b0-bd84-c3483182cefd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_d1d1353a-0004-43ca-8350-ac8bee084ca3" xlink:to="loc_us-gaap_CollateralDomain_9db96358-3b29-46b0-bd84-c3483182cefd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_86acbbc7-7731-4ac1-b77c-51d2cf432cd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_9db96358-3b29-46b0-bd84-c3483182cefd" xlink:to="loc_us-gaap_ResidentialRealEstateMember_86acbbc7-7731-4ac1-b77c-51d2cf432cd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FinancingReceivableExcludingAccruedInterestModificationPeriod_5e9a4a09-1137-4756-a709-7edfe499bdaa" xlink:href="rnst-20250930.xsd#rnst_FinancingReceivableExcludingAccruedInterestModificationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_41052e30-cb7d-40bf-a61a-7adfa82e3959" xlink:to="loc_rnst_FinancingReceivableExcludingAccruedInterestModificationPeriod_5e9a4a09-1137-4756-a709-7edfe499bdaa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent_46aa2dae-2deb-43e1-be85-acf25fc75f42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_41052e30-cb7d-40bf-a61a-7adfa82e3959" xlink:to="loc_us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent_46aa2dae-2deb-43e1-be85-acf25fc75f42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification_4f3ff22f-f003-438a-aea5-a10dec05af0b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_41052e30-cb7d-40bf-a61a-7adfa82e3959" xlink:to="loc_us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification_4f3ff22f-f003-438a-aea5-a10dec05af0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification_aa45175d-29aa-49d0-919b-c36a7a57d203" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_41052e30-cb7d-40bf-a61a-7adfa82e3959" xlink:to="loc_us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification_aa45175d-29aa-49d0-919b-c36a7a57d203" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/LoansLoanPortfoliobyRiskRatingGradesDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#LoansLoanPortfoliobyRiskRatingGradesDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/LoansLoanPortfoliobyRiskRatingGradesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_fc9e3254-1ce7-4dbe-ba9f-6d69a8adaeeb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_fc9e3254-1ce7-4dbe-ba9f-6d69a8adaeeb" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_43c20696-8c67-4591-91ee-7e47d9f584be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_43c20696-8c67-4591-91ee-7e47d9f584be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_43c20696-8c67-4591-91ee-7e47d9f584be_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_43c20696-8c67-4591-91ee-7e47d9f584be" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_43c20696-8c67-4591-91ee-7e47d9f584be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_43c20696-8c67-4591-91ee-7e47d9f584be" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialLoanMember_5b40eaa3-1028-4234-84e4-bfe2d3abfecf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:to="loc_us-gaap_CommercialLoanMember_5b40eaa3-1028-4234-84e4-bfe2d3abfecf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LeaseFinancingMember_84d70118-a122-47b0-aca4-f177e23f959c" xlink:href="rnst-20250930.xsd#rnst_LeaseFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:to="loc_rnst_LeaseFinancingMember_84d70118-a122-47b0-aca4-f177e23f959c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember_f83db072-1e48-465d-9cc4-5a71321367ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:to="loc_us-gaap_ConstructionLoansMember_f83db072-1e48-465d-9cc4-5a71321367ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RealEstateOneToFourFamilyMortgageMember_a549764b-f09b-4821-a740-1bcf28fa966f" xlink:href="rnst-20250930.xsd#rnst_RealEstateOneToFourFamilyMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:to="loc_rnst_RealEstateOneToFourFamilyMortgageMember_a549764b-f09b-4821-a740-1bcf28fa966f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialResidentialMortgageMember_94601c07-6609-4cc9-8df5-6f7a68eaf5da" xlink:href="rnst-20250930.xsd#rnst_CommercialResidentialMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:to="loc_rnst_CommercialResidentialMortgageMember_94601c07-6609-4cc9-8df5-6f7a68eaf5da" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InstallmentLoansToIndividualsMember_e3db6053-c36e-4feb-8f47-c3f2803e44ff" xlink:href="rnst-20250930.xsd#rnst_InstallmentLoansToIndividualsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_57c30b9a-64db-4acb-830a-f2f67e7b6cf1" xlink:to="loc_rnst_InstallmentLoansToIndividualsMember_e3db6053-c36e-4feb-8f47-c3f2803e44ff" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_6bf7ff06-cd3c-44dc-a764-211ab3ef3696" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:to="loc_us-gaap_CollateralAxis_6bf7ff06-cd3c-44dc-a764-211ab3ef3696" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_6bf7ff06-cd3c-44dc-a764-211ab3ef3696_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_6bf7ff06-cd3c-44dc-a764-211ab3ef3696" xlink:to="loc_us-gaap_CollateralDomain_6bf7ff06-cd3c-44dc-a764-211ab3ef3696_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_e0440d1f-f1ea-4a19-9139-3ff86b48da1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_6bf7ff06-cd3c-44dc-a764-211ab3ef3696" xlink:to="loc_us-gaap_CollateralDomain_e0440d1f-f1ea-4a19-9139-3ff86b48da1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_8ba5a623-5907-4b6a-b95a-58e2afe95488" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_e0440d1f-f1ea-4a19-9139-3ff86b48da1d" xlink:to="loc_us-gaap_ResidentialRealEstateMember_8ba5a623-5907-4b6a-b95a-58e2afe95488" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_635ca7c3-1f7d-4b0f-a7a3-adcc95fe7dfc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_e0440d1f-f1ea-4a19-9139-3ff86b48da1d" xlink:to="loc_us-gaap_CommercialRealEstateMember_635ca7c3-1f7d-4b0f-a7a3-adcc95fe7dfc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoansAxis_e47c8a8a-725b-4898-8a79-58331d167860" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoansAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:to="loc_us-gaap_ParticipatingMortgageLoansAxis_e47c8a8a-725b-4898-8a79-58331d167860" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_e47c8a8a-725b-4898-8a79-58331d167860_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_e47c8a8a-725b-4898-8a79-58331d167860" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_e47c8a8a-725b-4898-8a79-58331d167860_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_e47c8a8a-725b-4898-8a79-58331d167860" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PrimaryMember_3a424f1a-be53-4b0c-ab87-7cda66e88261" xlink:href="rnst-20250930.xsd#rnst_PrimaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:to="loc_rnst_PrimaryMember_3a424f1a-be53-4b0c-ab87-7cda66e88261" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HomeEquityLoanMember_b4cbc92e-1f38-4656-95bf-5084c1741b12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HomeEquityLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:to="loc_us-gaap_HomeEquityLoanMember_b4cbc92e-1f38-4656-95bf-5084c1741b12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RentalInvestmentMember_ff09258d-7537-4474-a3e8-922a7dce7408" xlink:href="rnst-20250930.xsd#rnst_RentalInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:to="loc_rnst_RentalInvestmentMember_ff09258d-7537-4474-a3e8-922a7dce7408" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialLandDevelopmentMember_6f9ca588-0f59-48d8-ad38-ce9e809a544a" xlink:href="rnst-20250930.xsd#rnst_CommercialLandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:to="loc_rnst_CommercialLandDevelopmentMember_6f9ca588-0f59-48d8-ad38-ce9e809a544a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OwnerOccupiedMember_c96e4b5d-59c5-4d3f-9bd6-4cefe4d4202b" xlink:href="rnst-20250930.xsd#rnst_OwnerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:to="loc_rnst_OwnerOccupiedMember_c96e4b5d-59c5-4d3f-9bd6-4cefe4d4202b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NonownerOccupiedMember_f4e028a6-985a-45c6-82b8-d4297a146728" xlink:href="rnst-20250930.xsd#rnst_NonownerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_ac69a95c-f778-4b67-b12a-daa4a2944f30" xlink:to="loc_rnst_NonownerOccupiedMember_f4e028a6-985a-45c6-82b8-d4297a146728" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_34c021c6-115d-40e3-8ba9-91b9d860068c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentPerformanceStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_34c021c6-115d-40e3-8ba9-91b9d860068c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_34c021c6-115d-40e3-8ba9-91b9d860068c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_34c021c6-115d-40e3-8ba9-91b9d860068c" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_34c021c6-115d-40e3-8ba9-91b9d860068c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_e59576d6-4efc-4dc2-b03b-0099777d4b21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_34c021c6-115d-40e3-8ba9-91b9d860068c" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_e59576d6-4efc-4dc2-b03b-0099777d4b21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformingFinancingReceivableMember_0e119cc7-41e3-40eb-a94d-9f83fe7c8516" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PerformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_e59576d6-4efc-4dc2-b03b-0099777d4b21" xlink:to="loc_us-gaap_PerformingFinancingReceivableMember_0e119cc7-41e3-40eb-a94d-9f83fe7c8516" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonperformingFinancingReceivableMember_dc5b5fa0-0e55-45f9-b9bf-a967bc5b696f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonperformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_e59576d6-4efc-4dc2-b03b-0099777d4b21" xlink:to="loc_us-gaap_NonperformingFinancingReceivableMember_dc5b5fa0-0e55-45f9-b9bf-a967bc5b696f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_68043a0d-6879-4505-9c9c-2858110434cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_8ff427c0-5e6a-44ed-85b9-beb0fabd9ff1" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_68043a0d-6879-4505-9c9c-2858110434cd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_68043a0d-6879-4505-9c9c-2858110434cd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_68043a0d-6879-4505-9c9c-2858110434cd" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_68043a0d-6879-4505-9c9c-2858110434cd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_68043a0d-6879-4505-9c9c-2858110434cd" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_SubjecttoCreditRiskAssessmentMember_beff552a-a95c-4f8e-b9fe-a9a60caf6654" xlink:href="rnst-20250930.xsd#rnst_SubjecttoCreditRiskAssessmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:to="loc_rnst_SubjecttoCreditRiskAssessmentMember_beff552a-a95c-4f8e-b9fe-a9a60caf6654" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PassMember_5855fe4c-7644-4d45-b86a-598ba932b568" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PassMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:to="loc_us-gaap_PassMember_5855fe4c-7644-4d45-b86a-598ba932b568" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SpecialMentionMember_cf88d6ab-5960-4421-a49f-bf1a0725140e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SpecialMentionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:to="loc_us-gaap_SpecialMentionMember_cf88d6ab-5960-4421-a49f-bf1a0725140e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_WatchMember_53ba3c69-4b27-489d-ae1d-773fa97a871e" xlink:href="rnst-20250930.xsd#rnst_WatchMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:to="loc_rnst_WatchMember_53ba3c69-4b27-489d-ae1d-773fa97a871e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ClassifiedMember_b3e15ea6-186e-4031-ba9a-ab04ed47818d" xlink:href="rnst-20250930.xsd#rnst_ClassifiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:to="loc_rnst_ClassifiedMember_b3e15ea6-186e-4031-ba9a-ab04ed47818d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NotSubjecttoCreditRiskAssessmentMember_70791aeb-7b1e-42e4-bf68-bc624e60a1fd" xlink:href="rnst-20250930.xsd#rnst_NotSubjecttoCreditRiskAssessmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_e5d0724f-44fe-4b22-93de-65caf58e5a9d" xlink:to="loc_rnst_NotSubjecttoCreditRiskAssessmentMember_70791aeb-7b1e-42e4-bf68-bc624e60a1fd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:href="rnst-20250930.xsd#rnst_LoanPortfolioByRiskRatingGradesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_fc9e3254-1ce7-4dbe-ba9f-6d69a8adaeeb" xlink:to="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_08c9c57c-5987-4366-90e3-03bd3b197018" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_08c9c57c-5987-4366-90e3-03bd3b197018" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_8097eabf-0835-4e89-b333-67d205ba9527" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_8097eabf-0835-4e89-b333-67d205ba9527" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_2c347be9-f95d-45f5-a25f-58ae93685ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_2c347be9-f95d-45f5-a25f-58ae93685ca1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_abf12806-4156-4bca-8a22-fdb4ad2a5f41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_abf12806-4156-4bca-8a22-fdb4ad2a5f41" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_9152e5da-e2d9-4ad0-b2b2-5d098cec89bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_9152e5da-e2d9-4ad0-b2b2-5d098cec89bc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_f7f579f2-9566-4f95-bcb9-1e5bbeff6cb5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_f7f579f2-9566-4f95-bcb9-1e5bbeff6cb5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_4c27a90b-8c63-4929-9ceb-1515244ef991" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolving"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_4c27a90b-8c63-4929-9ceb-1515244ef991" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan_9c5af945-9034-4825-86dc-a8e86966d6c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan_9c5af945-9034-4825-86dc-a8e86966d6c5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_99e382e9-9e0b-406b-83d6-e2f889eceefa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_LoanPortfolioByRiskRatingGradesAbstract_cd105a05-a544-4f43-ad64-0f34136c07b9" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_99e382e9-9e0b-406b-83d6-e2f889eceefa" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/LoansGrossChargeOffsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#LoansGrossChargeOffsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/LoansGrossChargeOffsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3556e079-1455-490b-a107-21a28c578da6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_edf93d12-546d-48ba-b650-da5071fe1682" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3556e079-1455-490b-a107-21a28c578da6" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_edf93d12-546d-48ba-b650-da5071fe1682" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_c88a6779-68a3-43e8-8fb9-96e9353756ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_edf93d12-546d-48ba-b650-da5071fe1682" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_c88a6779-68a3-43e8-8fb9-96e9353756ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_c88a6779-68a3-43e8-8fb9-96e9353756ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_c88a6779-68a3-43e8-8fb9-96e9353756ab" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_c88a6779-68a3-43e8-8fb9-96e9353756ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_c88a6779-68a3-43e8-8fb9-96e9353756ab" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialLoanMember_315a4c01-133f-4165-8522-91dfd1dbb015" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:to="loc_us-gaap_CommercialLoanMember_315a4c01-133f-4165-8522-91dfd1dbb015" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LeaseFinancingMember_213c5735-1e81-49c3-91c9-039b6a72de7f" xlink:href="rnst-20250930.xsd#rnst_LeaseFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:to="loc_rnst_LeaseFinancingMember_213c5735-1e81-49c3-91c9-039b6a72de7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember_d5e19d8f-c219-44b6-becf-32ce9cb39658" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:to="loc_us-gaap_ConstructionLoansMember_d5e19d8f-c219-44b6-becf-32ce9cb39658" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RealEstateOneToFourFamilyMortgageMember_9eac7ec6-845b-46ff-a862-570edeaa448f" xlink:href="rnst-20250930.xsd#rnst_RealEstateOneToFourFamilyMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:to="loc_rnst_RealEstateOneToFourFamilyMortgageMember_9eac7ec6-845b-46ff-a862-570edeaa448f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialResidentialMortgageMember_2cd5bb8b-2960-4aa9-97bd-7b86f253162b" xlink:href="rnst-20250930.xsd#rnst_CommercialResidentialMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:to="loc_rnst_CommercialResidentialMortgageMember_2cd5bb8b-2960-4aa9-97bd-7b86f253162b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InstallmentLoansToIndividualsMember_b36ae5b8-7e78-4541-b286-db38df88c734" xlink:href="rnst-20250930.xsd#rnst_InstallmentLoansToIndividualsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_aae06d0a-1a44-44ac-a7eb-752614148baf" xlink:to="loc_rnst_InstallmentLoansToIndividualsMember_b36ae5b8-7e78-4541-b286-db38df88c734" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoansAxis_d6e2ee48-4f2b-4fd0-9baf-74e74eab8f02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoansAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_edf93d12-546d-48ba-b650-da5071fe1682" xlink:to="loc_us-gaap_ParticipatingMortgageLoansAxis_d6e2ee48-4f2b-4fd0-9baf-74e74eab8f02" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_d6e2ee48-4f2b-4fd0-9baf-74e74eab8f02_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_d6e2ee48-4f2b-4fd0-9baf-74e74eab8f02" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_d6e2ee48-4f2b-4fd0-9baf-74e74eab8f02_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParticipatingMortgageLoanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ParticipatingMortgageLoansAxis_d6e2ee48-4f2b-4fd0-9baf-74e74eab8f02" xlink:to="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_PrimaryMember_e2a13a25-b14d-4f00-96a1-2304c9b0fe88" xlink:href="rnst-20250930.xsd#rnst_PrimaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:to="loc_rnst_PrimaryMember_e2a13a25-b14d-4f00-96a1-2304c9b0fe88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HomeEquityLoanMember_0eba1cdd-ca66-47d3-926a-4f0cfe0698d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HomeEquityLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:to="loc_us-gaap_HomeEquityLoanMember_0eba1cdd-ca66-47d3-926a-4f0cfe0698d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RentalInvestmentMember_2eba6bba-e881-4eca-9959-440c4a392f7f" xlink:href="rnst-20250930.xsd#rnst_RentalInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:to="loc_rnst_RentalInvestmentMember_2eba6bba-e881-4eca-9959-440c4a392f7f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OwnerOccupiedMember_4e85108f-73e6-41ce-b684-ac091b6144ed" xlink:href="rnst-20250930.xsd#rnst_OwnerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:to="loc_rnst_OwnerOccupiedMember_4e85108f-73e6-41ce-b684-ac091b6144ed" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_NonownerOccupiedMember_190d1f47-518e-44ae-8393-d1101fd8bff8" xlink:href="rnst-20250930.xsd#rnst_NonownerOccupiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:to="loc_rnst_NonownerOccupiedMember_190d1f47-518e-44ae-8393-d1101fd8bff8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LandDevelopmentMember_a46a49b8-518e-48a9-93cd-dfc8eeccf934" xlink:href="rnst-20250930.xsd#rnst_LandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParticipatingMortgageLoanNameDomain_39dba6ab-8ab4-4b5f-b48c-91bf04a3f8a1" xlink:to="loc_rnst_LandDevelopmentMember_a46a49b8-518e-48a9-93cd-dfc8eeccf934" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_b77ff8d8-49c5-40ef-8934-6eeac33dc4a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_edf93d12-546d-48ba-b650-da5071fe1682" xlink:to="loc_us-gaap_CollateralAxis_b77ff8d8-49c5-40ef-8934-6eeac33dc4a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_b77ff8d8-49c5-40ef-8934-6eeac33dc4a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_b77ff8d8-49c5-40ef-8934-6eeac33dc4a1" xlink:to="loc_us-gaap_CollateralDomain_b77ff8d8-49c5-40ef-8934-6eeac33dc4a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_632cefea-ba3d-46d7-902d-ff754319dc11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_b77ff8d8-49c5-40ef-8934-6eeac33dc4a1" xlink:to="loc_us-gaap_CollateralDomain_632cefea-ba3d-46d7-902d-ff754319dc11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_ac462c98-8ef6-4eb2-8f09-0092640d96d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_632cefea-ba3d-46d7-902d-ff754319dc11" xlink:to="loc_us-gaap_ResidentialRealEstateMember_ac462c98-8ef6-4eb2-8f09-0092640d96d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_3556e079-1455-490b-a107-21a28c578da6" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_64b3d24c-c9ab-4604-b781-8d9d99038363" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_64b3d24c-c9ab-4604-b781-8d9d99038363" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_2831942b-a302-4721-ba1a-4b2e682bedac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_2831942b-a302-4721-ba1a-4b2e682bedac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_3630893a-9266-43f8-8e11-087a453ed858" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_3630893a-9266-43f8-8e11-087a453ed858" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_9bc349e1-dbbd-4309-8e65-e5c7af24879b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_9bc349e1-dbbd-4309-8e65-e5c7af24879b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_22dfc720-2bc8-46a0-bf84-e4a33dfbdf6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_22dfc720-2bc8-46a0-bf84-e4a33dfbdf6d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_adea03f9-b729-4ef2-a43c-c81864a96d1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_adea03f9-b729-4ef2-a43c-c81864a96d1a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff_d6bbcbb9-73cc-43f9-848f-917709a455a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff_d6bbcbb9-73cc-43f9-848f-917709a455a9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_0e81f7c1-a83a-436b-9ea7-b998b722dca1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffByOriginationYearAbstract_91ff0d81-f247-447d-8c55-7a86a84a230e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_0e81f7c1-a83a-436b-9ea7-b998b722dca1" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/AllowanceforCreditLossesRollForwardOftheAllowanceforLoanLossesDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#AllowanceforCreditLossesRollForwardOftheAllowanceforLoanLossesDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/AllowanceforCreditLossesRollForwardOftheAllowanceforLoanLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_9ef05b01-1053-48cd-b4c4-04d8ccc9b2f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_cfe1d947-e4f6-4c52-9b49-cc70201f4cde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_9ef05b01-1053-48cd-b4c4-04d8ccc9b2f1" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_cfe1d947-e4f6-4c52-9b49-cc70201f4cde" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_3da7e573-64bd-424a-a580-f3fed963e571" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_cfe1d947-e4f6-4c52-9b49-cc70201f4cde" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_3da7e573-64bd-424a-a580-f3fed963e571" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_3da7e573-64bd-424a-a580-f3fed963e571_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_3da7e573-64bd-424a-a580-f3fed963e571" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_3da7e573-64bd-424a-a580-f3fed963e571_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_3da7e573-64bd-424a-a580-f3fed963e571" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialLoanMember_db61395e-5433-40fa-84d2-19ed7db921a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:to="loc_us-gaap_CommercialLoanMember_db61395e-5433-40fa-84d2-19ed7db921a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionLoansMember_533a41d8-1bfb-423a-ab71-26451386fed3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:to="loc_us-gaap_ConstructionLoansMember_533a41d8-1bfb-423a-ab71-26451386fed3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RealEstateOneToFourFamilyMortgageMember_478f60f5-ab4c-4688-82ea-af3aedc8fdf4" xlink:href="rnst-20250930.xsd#rnst_RealEstateOneToFourFamilyMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:to="loc_rnst_RealEstateOneToFourFamilyMortgageMember_478f60f5-ab4c-4688-82ea-af3aedc8fdf4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialResidentialMortgageMember_e9ef94fd-535d-4f8c-b060-5f8bdb8fcf42" xlink:href="rnst-20250930.xsd#rnst_CommercialResidentialMortgageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:to="loc_rnst_CommercialResidentialMortgageMember_e9ef94fd-535d-4f8c-b060-5f8bdb8fcf42" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_LeaseFinancingMember_73892f32-6376-4254-adfc-2dad19c63560" xlink:href="rnst-20250930.xsd#rnst_LeaseFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:to="loc_rnst_LeaseFinancingMember_73892f32-6376-4254-adfc-2dad19c63560" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InstallmentLoansToIndividualsMember_f56da4c1-fa5f-41b0-94b0-3f3f0e4c527f" xlink:href="rnst-20250930.xsd#rnst_InstallmentLoansToIndividualsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_499957d8-575c-4b08-bd63-ca51bb0d35a6" xlink:to="loc_rnst_InstallmentLoansToIndividualsMember_f56da4c1-fa5f-41b0-94b0-3f3f0e4c527f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_49e28322-2a67-455a-bc84-2371f2500f3b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_cfe1d947-e4f6-4c52-9b49-cc70201f4cde" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_49e28322-2a67-455a-bc84-2371f2500f3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_49e28322-2a67-455a-bc84-2371f2500f3b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_49e28322-2a67-455a-bc84-2371f2500f3b" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_49e28322-2a67-455a-bc84-2371f2500f3b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_2e91905b-c067-481b-8241-62ba399440d1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionAxis_49e28322-2a67-455a-bc84-2371f2500f3b" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_2e91905b-c067-481b-8241-62ba399440d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_9cf98c33-da1c-438a-bbf3-b6a87215403e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_CumulativeEffectPeriodOfAdoptionDomain_2e91905b-c067-481b-8241-62ba399440d1" xlink:to="loc_srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_9cf98c33-da1c-438a-bbf3-b6a87215403e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_9ef05b01-1053-48cd-b4c4-04d8ccc9b2f1" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_573cb8c7-529e-4515-aa4f-6dbc94231752" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_573cb8c7-529e-4515-aa4f-6dbc94231752" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_e57fdc0f-fb32-4cf0-8a18-00cf4166f660" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_e57fdc0f-fb32-4cf0-8a18-00cf4166f660" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_2609c329-d89c-4032-81bf-2f1ff0b6253e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_2609c329-d89c-4032-81bf-2f1ff0b6253e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_c85f96ec-e3b4-4d8c-afa1-1993702678e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_c85f96ec-e3b4-4d8c-afa1-1993702678e1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_1ab482ce-7350-495b-bd61-fdf4bd28e4ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRollForward_aa92524d-42ee-489c-9c88-ca2c80848c7b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_1ab482ce-7350-495b-bd61-fdf4bd28e4ae" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_3a4e394f-e601-483f-97fb-72d4d5309c80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance_38511f13-560b-4c1d-b8b8-87cbfd6aa298" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_9ef05b01-1053-48cd-b4c4-04d8ccc9b2f1" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance_38511f13-560b-4c1d-b8b8-87cbfd6aa298" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/OtherRealEstateOwnedCoveredandNotCoveredUnderaLossShareAgreementNetofValuationAllowancesandDirectWriteDownsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#OtherRealEstateOwnedCoveredandNotCoveredUnderaLossShareAgreementNetofValuationAllowancesandDirectWriteDownsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/OtherRealEstateOwnedCoveredandNotCoveredUnderaLossShareAgreementNetofValuationAllowancesandDirectWriteDownsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstatePropertiesLineItems_3b971f66-9f19-4ec4-9bf1-fd9a1c81e124" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstatePropertiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRealEstatePropertiesTable_7bfab6f6-ec57-44b6-bab1-38f8d8bad029" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRealEstatePropertiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_3b971f66-9f19-4ec4-9bf1-fd9a1c81e124" xlink:to="loc_us-gaap_ScheduleOfRealEstatePropertiesTable_7bfab6f6-ec57-44b6-bab1-38f8d8bad029" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_412bbd91-0c83-480f-afdf-6476316dc4b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRealEstatePropertiesTable_7bfab6f6-ec57-44b6-bab1-38f8d8bad029" xlink:to="loc_us-gaap_CollateralAxis_412bbd91-0c83-480f-afdf-6476316dc4b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_412bbd91-0c83-480f-afdf-6476316dc4b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_412bbd91-0c83-480f-afdf-6476316dc4b5" xlink:to="loc_us-gaap_CollateralDomain_412bbd91-0c83-480f-afdf-6476316dc4b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_821970ed-e536-4dd5-bfe5-bf2a9abf23c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_412bbd91-0c83-480f-afdf-6476316dc4b5" xlink:to="loc_us-gaap_CollateralDomain_821970ed-e536-4dd5-bfe5-bf2a9abf23c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_507be857-b393-478d-852c-cc294f32c630" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_821970ed-e536-4dd5-bfe5-bf2a9abf23c1" xlink:to="loc_us-gaap_ResidentialRealEstateMember_507be857-b393-478d-852c-cc294f32c630" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_92392fe7-c503-4cbb-ab7e-b6990d366e2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_821970ed-e536-4dd5-bfe5-bf2a9abf23c1" xlink:to="loc_us-gaap_CommercialRealEstateMember_92392fe7-c503-4cbb-ab7e-b6990d366e2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ResidentialLandDevelopmentMember_2e398c6d-079a-4874-b3db-6da50cd5ac49" xlink:href="rnst-20250930.xsd#rnst_ResidentialLandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_821970ed-e536-4dd5-bfe5-bf2a9abf23c1" xlink:to="loc_rnst_ResidentialLandDevelopmentMember_2e398c6d-079a-4874-b3db-6da50cd5ac49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommercialLandDevelopmentMember_4d0906e6-6d5a-4951-be1b-1a29f6d3d63b" xlink:href="rnst-20250930.xsd#rnst_CommercialLandDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_821970ed-e536-4dd5-bfe5-bf2a9abf23c1" xlink:to="loc_rnst_CommercialLandDevelopmentMember_4d0906e6-6d5a-4951-be1b-1a29f6d3d63b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRealEstateAndForeclosedAssets_276de7ec-613d-43ce-81db-28ecea412627" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherRealEstateAndForeclosedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_3b971f66-9f19-4ec4-9bf1-fd9a1c81e124" xlink:to="loc_us-gaap_OtherRealEstateAndForeclosedAssets_276de7ec-613d-43ce-81db-28ecea412627" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/OtherRealEstateOwnedComponentsofOREOintheConsolidatedStatementsofIncomeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#OtherRealEstateOwnedComponentsofOREOintheConsolidatedStatementsofIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/OtherRealEstateOwnedComponentsofOREOintheConsolidatedStatementsofIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstatePropertiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRealEstatePropertiesTable_3a78229f-9301-42dc-afb3-4d014a4b4bdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRealEstatePropertiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_us-gaap_ScheduleOfRealEstatePropertiesTable_3a78229f-9301-42dc-afb3-4d014a4b4bdc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_ef7ec02a-1823-4365-ac1c-b90b06dc226f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRealEstatePropertiesTable_3a78229f-9301-42dc-afb3-4d014a4b4bdc" xlink:to="loc_us-gaap_CollateralAxis_ef7ec02a-1823-4365-ac1c-b90b06dc226f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_ef7ec02a-1823-4365-ac1c-b90b06dc226f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_ef7ec02a-1823-4365-ac1c-b90b06dc226f" xlink:to="loc_us-gaap_CollateralDomain_ef7ec02a-1823-4365-ac1c-b90b06dc226f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_f0de7d61-f7f5-4067-85e6-8ef6f4280370" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_ef7ec02a-1823-4365-ac1c-b90b06dc226f" xlink:to="loc_us-gaap_CollateralDomain_f0de7d61-f7f5-4067-85e6-8ef6f4280370" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResidentialRealEstateMember_9e96993b-34c1-44c4-bf33-097aca3e4eaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResidentialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_f0de7d61-f7f5-4067-85e6-8ef6f4280370" xlink:to="loc_us-gaap_ResidentialRealEstateMember_9e96993b-34c1-44c4-bf33-097aca3e4eaa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateAmortizedCostOfLoansInForeclosure_7600c548-5355-452f-be8e-e2f7867ddc70" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateAmortizedCostOfLoansInForeclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_rnst_OtherRealEstateAmortizedCostOfLoansInForeclosure_7600c548-5355-452f-be8e-e2f7867ddc70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfPropertyRepairsAndMaintenance_c5ca9cec-e216-4c9f-a61e-901966840085" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfPropertyRepairsAndMaintenance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_us-gaap_CostOfPropertyRepairsAndMaintenance_c5ca9cec-e216-4c9f-a61e-901966840085" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateTaxesAndInsurance_b9b69a83-b53e-4717-9002-db0e12fc044b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateTaxesAndInsurance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_us-gaap_RealEstateTaxesAndInsurance_b9b69a83-b53e-4717-9002-db0e12fc044b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedImpairments_c43d10c3-4564-4396-b468-42d21628d531" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedImpairments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_rnst_OtherRealEstateOwnedImpairments_c43d10c3-4564-4396-b468-42d21628d531" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnSalesOfOtherRealEstate_a922b0da-7182-4e3d-804c-265b81d51357" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnSalesOfOtherRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_us-gaap_GainsLossesOnSalesOfOtherRealEstate_a922b0da-7182-4e3d-804c-265b81d51357" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedRentalIncome_04ebe7eb-7173-43e2-b27c-4b3017ecc07c" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedRentalIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_rnst_OtherRealEstateOwnedRentalIncome_04ebe7eb-7173-43e2-b27c-4b3017ecc07c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ForeclosedRealEstateExpenseNet_21720f69-55b7-4b19-b212-d1d01a642274" xlink:href="rnst-20250930.xsd#rnst_ForeclosedRealEstateExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstatePropertiesLineItems_62289ac3-023a-4f7d-9ed9-107a9bcf5be1" xlink:to="loc_rnst_ForeclosedRealEstateExpenseNet_21720f69-55b7-4b19-b212-d1d01a642274" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsCarryingAmountsofGoodwillbyOperatingSegmentsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#GoodwillandOtherIntangibleAssetsCarryingAmountsofGoodwillbyOperatingSegmentsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsCarryingAmountsofGoodwillbyOperatingSegmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_0959ccc9-bb4e-48d9-9ad3-a2963e4995f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_cbaf7520-7ba5-4bbd-a5b9-a77d3c9ce537" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_0959ccc9-bb4e-48d9-9ad3-a2963e4995f4" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_cbaf7520-7ba5-4bbd-a5b9-a77d3c9ce537" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_b4208638-6cee-4318-95ef-0baa331be4b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_cbaf7520-7ba5-4bbd-a5b9-a77d3c9ce537" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_b4208638-6cee-4318-95ef-0baa331be4b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_b4208638-6cee-4318-95ef-0baa331be4b2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b4208638-6cee-4318-95ef-0baa331be4b2" xlink:to="loc_us-gaap_SegmentDomain_b4208638-6cee-4318-95ef-0baa331be4b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_5d812b32-ab6c-4492-a65e-78964026d694" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b4208638-6cee-4318-95ef-0baa331be4b2" xlink:to="loc_us-gaap_SegmentDomain_5d812b32-ab6c-4492-a65e-78964026d694" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommunityBanksMember_e184d9f0-7cb7-4516-b97a-474117ba5790" xlink:href="rnst-20250930.xsd#rnst_CommunityBanksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5d812b32-ab6c-4492-a65e-78964026d694" xlink:to="loc_rnst_CommunityBanksMember_e184d9f0-7cb7-4516-b97a-474117ba5790" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InsuranceMember_a3751589-12df-46ef-a804-f8874df122ab" xlink:href="rnst-20250930.xsd#rnst_InsuranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5d812b32-ab6c-4492-a65e-78964026d694" xlink:to="loc_rnst_InsuranceMember_a3751589-12df-46ef-a804-f8874df122ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_b9a208b1-eef2-4542-8b1d-17b460fd3a63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_0959ccc9-bb4e-48d9-9ad3-a2963e4995f4" xlink:to="loc_us-gaap_GoodwillRollForward_b9a208b1-eef2-4542-8b1d-17b460fd3a63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_33a5c96b-7420-41df-bbb5-2884f012872d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_b9a208b1-eef2-4542-8b1d-17b460fd3a63" xlink:to="loc_us-gaap_Goodwill_33a5c96b-7420-41df-bbb5-2884f012872d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_c5ce5888-e12b-49ed-9c05-1b1e2132a313" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_b9a208b1-eef2-4542-8b1d-17b460fd3a63" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_c5ce5888-e12b-49ed-9c05-1b1e2132a313" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_7b64f5e6-07dd-425e-b67b-849e2fd18115" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_b9a208b1-eef2-4542-8b1d-17b460fd3a63" xlink:to="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_7b64f5e6-07dd-425e-b67b-849e2fd18115" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_3785d519-3964-4345-8038-4a904a491d8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsSummaryofFiniteLivedIntangibleAssetsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#GoodwillandOtherIntangibleAssetsSummaryofFiniteLivedIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsSummaryofFiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_85fe7388-ea35-45f8-abc0-1b2858980cfa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_3dbb8f0e-d56d-4bfc-a003-1b97bce01c3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_85fe7388-ea35-45f8-abc0-1b2858980cfa" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_3dbb8f0e-d56d-4bfc-a003-1b97bce01c3b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd937e59-f06a-48da-bd01-9586c24b0565" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_3dbb8f0e-d56d-4bfc-a003-1b97bce01c3b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd937e59-f06a-48da-bd01-9586c24b0565" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dd937e59-f06a-48da-bd01-9586c24b0565_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd937e59-f06a-48da-bd01-9586c24b0565" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dd937e59-f06a-48da-bd01-9586c24b0565_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f6678cca-3d05-4f02-8ccf-c7391a3578ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_dd937e59-f06a-48da-bd01-9586c24b0565" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f6678cca-3d05-4f02-8ccf-c7391a3578ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CoreDepositsMember_83cd584e-1cdc-4bea-8a03-8c75c0e0b2cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CoreDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f6678cca-3d05-4f02-8ccf-c7391a3578ba" xlink:to="loc_us-gaap_CoreDepositsMember_83cd584e-1cdc-4bea-8a03-8c75c0e0b2cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_ed4b15ad-b3e6-47e7-abc8-4667ac75a864" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f6678cca-3d05-4f02-8ccf-c7391a3578ba" xlink:to="loc_us-gaap_CustomerRelationshipsMember_ed4b15ad-b3e6-47e7-abc8-4667ac75a864" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_1d395f8f-f162-4391-8b0f-1ee01a02494e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_85fe7388-ea35-45f8-abc0-1b2858980cfa" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_1d395f8f-f162-4391-8b0f-1ee01a02494e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_c596bb25-e1bd-490c-a958-e7f6fd5265cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_1d395f8f-f162-4391-8b0f-1ee01a02494e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_c596bb25-e1bd-490c-a958-e7f6fd5265cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_c484d2d5-7941-4782-957a-19962f86f989" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_1d395f8f-f162-4391-8b0f-1ee01a02494e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_c484d2d5-7941-4782-957a-19962f86f989" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_89db4428-8429-49af-a02e-031b14aa81b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_1d395f8f-f162-4391-8b0f-1ee01a02494e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_89db4428-8429-49af-a02e-031b14aa81b1" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsCurrentYearAmortizationExpenseforFiniteLivedIntangibleAssetsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#GoodwillandOtherIntangibleAssetsCurrentYearAmortizationExpenseforFiniteLivedIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsCurrentYearAmortizationExpenseforFiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_f84d745c-9b95-4ab4-ab1f-2f7955f9855f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_37424df4-a8f7-4a03-a665-f58515a500f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_f84d745c-9b95-4ab4-ab1f-2f7955f9855f" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_37424df4-a8f7-4a03-a665-f58515a500f7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_2b44c04a-33f1-4eb5-a263-3fc11ff4e470" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_37424df4-a8f7-4a03-a665-f58515a500f7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_2b44c04a-33f1-4eb5-a263-3fc11ff4e470" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2b44c04a-33f1-4eb5-a263-3fc11ff4e470_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_2b44c04a-33f1-4eb5-a263-3fc11ff4e470" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2b44c04a-33f1-4eb5-a263-3fc11ff4e470_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f16ded70-288c-46e0-8f78-5c7c93b55e06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_2b44c04a-33f1-4eb5-a263-3fc11ff4e470" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f16ded70-288c-46e0-8f78-5c7c93b55e06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CoreDepositsMember_890e0d8a-1a65-416e-a832-9d8e18d9a8b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CoreDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f16ded70-288c-46e0-8f78-5c7c93b55e06" xlink:to="loc_us-gaap_CoreDepositsMember_890e0d8a-1a65-416e-a832-9d8e18d9a8b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_1d22a4fd-55cd-4ba4-a434-9bc77bb305b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f16ded70-288c-46e0-8f78-5c7c93b55e06" xlink:to="loc_us-gaap_CustomerRelationshipsMember_1d22a4fd-55cd-4ba4-a434-9bc77bb305b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_cc7ccabc-4639-418b-a808-ec274398443c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_f84d745c-9b95-4ab4-ab1f-2f7955f9855f" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_cc7ccabc-4639-418b-a808-ec274398443c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsEstimatedAmortizationExpenseofFiniteLivedIntangibleAssetsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#GoodwillandOtherIntangibleAssetsEstimatedAmortizationExpenseofFiniteLivedIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/GoodwillandOtherIntangibleAssetsEstimatedAmortizationExpenseofFiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_56162936-0ec0-45a4-8655-7cb0226b0bbe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_56162936-0ec0-45a4-8655-7cb0226b0bbe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8f868b4f-9b14-4d8d-ac27-c9bff552503b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_56162936-0ec0-45a4-8655-7cb0226b0bbe" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8f868b4f-9b14-4d8d-ac27-c9bff552503b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8f868b4f-9b14-4d8d-ac27-c9bff552503b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8f868b4f-9b14-4d8d-ac27-c9bff552503b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_8f868b4f-9b14-4d8d-ac27-c9bff552503b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_e443da4e-f400-491f-87bd-9d2347c491c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_8f868b4f-9b14-4d8d-ac27-c9bff552503b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_e443da4e-f400-491f-87bd-9d2347c491c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CoreDepositsMember_38655f06-28b1-4f2e-b96c-5f4972a0674e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CoreDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_e443da4e-f400-491f-87bd-9d2347c491c8" xlink:to="loc_us-gaap_CoreDepositsMember_38655f06-28b1-4f2e-b96c-5f4972a0674e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_4f4e3db8-2b9f-494d-ac1e-cdfa320f7121" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_e443da4e-f400-491f-87bd-9d2347c491c8" xlink:to="loc_us-gaap_CustomerRelationshipsMember_4f4e3db8-2b9f-494d-ac1e-cdfa320f7121" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_1b728b08-1465-44ad-baf9-81fda428552e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_1b728b08-1465-44ad-baf9-81fda428552e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_8cd56dcb-b529-487e-b9c7-418f055e65e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_8cd56dcb-b529-487e-b9c7-418f055e65e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_00d0b45d-898a-4717-ad75-adac15dc8425" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_00d0b45d-898a-4717-ad75-adac15dc8425" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_7ac18005-bc37-4889-95b0-6416923aed80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_7ac18005-bc37-4889-95b0-6416923aed80" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_d393f123-895f-419e-9757-c4189d7f6d74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_d393f123-895f-419e-9757-c4189d7f6d74" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_2808e7fc-f585-4d4b-9b53-034dc60b0385" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_df172c50-8a39-4f23-b0bf-7441f7c659cf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_2808e7fc-f585-4d4b-9b53-034dc60b0385" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/MortgageServicingRightsNarrativeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#MortgageServicingRightsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/MortgageServicingRightsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_048810c2-18ab-4480-a7bc-bac0e173123e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_7955d81e-99e9-41a0-ba42-da85bfff5d69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_048810c2-18ab-4480-a7bc-bac0e173123e" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_7955d81e-99e9-41a0-ba42-da85bfff5d69" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_3871f6a9-5d31-47c8-8bd5-6fcd30267534" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_7955d81e-99e9-41a0-ba42-da85bfff5d69" xlink:to="loc_srt_ProductOrServiceAxis_3871f6a9-5d31-47c8-8bd5-6fcd30267534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_3871f6a9-5d31-47c8-8bd5-6fcd30267534_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_3871f6a9-5d31-47c8-8bd5-6fcd30267534" xlink:to="loc_srt_ProductsAndServicesDomain_3871f6a9-5d31-47c8-8bd5-6fcd30267534_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_edc5b8f4-0e8f-4219-918d-0ba938c2cb75" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_3871f6a9-5d31-47c8-8bd5-6fcd30267534" xlink:to="loc_srt_ProductsAndServicesDomain_edc5b8f4-0e8f-4219-918d-0ba938c2cb75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankServicingMember_7a5e05f8-cd93-4848-a284-62bfc3164210" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankServicingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_edc5b8f4-0e8f-4219-918d-0ba938c2cb75" xlink:to="loc_us-gaap_BankServicingMember_7a5e05f8-cd93-4848-a284-62bfc3164210" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageServicingRightsMSRImpairmentRecovery_9e9f2f7f-d293-4db7-9dde-2689d40c8b0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MortgageServicingRightsMSRImpairmentRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_048810c2-18ab-4480-a7bc-bac0e173123e" xlink:to="loc_us-gaap_MortgageServicingRightsMSRImpairmentRecovery_9e9f2f7f-d293-4db7-9dde-2689d40c8b0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_12e4349e-af70-4f1c-b679-142ec6cee572" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_048810c2-18ab-4480-a7bc-bac0e173123e" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_12e4349e-af70-4f1c-b679-142ec6cee572" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/EmployeeBenefitandDeferredCompensationPlansPlanExpenseforNonContributoryBenefitPensionPlanandPostRetirementHealthandLifePlansDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#EmployeeBenefitandDeferredCompensationPlansPlanExpenseforNonContributoryBenefitPensionPlanandPostRetirementHealthandLifePlansDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/EmployeeBenefitandDeferredCompensationPlansPlanExpenseforNonContributoryBenefitPensionPlanandPostRetirementHealthandLifePlansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_88e3d64a-a224-4c60-8e48-ba3e28190303" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_379f8090-57c7-475f-8cb8-d2b5a479563c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_88e3d64a-a224-4c60-8e48-ba3e28190303" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_379f8090-57c7-475f-8cb8-d2b5a479563c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_ed1ed1ca-dd8a-4186-81f3-6e4847cad613" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_379f8090-57c7-475f-8cb8-d2b5a479563c" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_ed1ed1ca-dd8a-4186-81f3-6e4847cad613" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_ed1ed1ca-dd8a-4186-81f3-6e4847cad613_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_ed1ed1ca-dd8a-4186-81f3-6e4847cad613" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_ed1ed1ca-dd8a-4186-81f3-6e4847cad613_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_a133415b-a7b4-471b-8d93-55f41c15a7da" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_ed1ed1ca-dd8a-4186-81f3-6e4847cad613" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_a133415b-a7b4-471b-8d93-55f41c15a7da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_c2c2acb0-a5d0-408b-8194-902efab57c18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_a133415b-a7b4-471b-8d93-55f41c15a7da" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_c2c2acb0-a5d0-408b-8194-902efab57c18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPensionPlansDefinedBenefitMember_fb05b3f4-fba8-4cea-ac56-206d9ebd8e17" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherPensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_a133415b-a7b4-471b-8d93-55f41c15a7da" xlink:to="loc_us-gaap_OtherPensionPlansDefinedBenefitMember_fb05b3f4-fba8-4cea-ac56-206d9ebd8e17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_ebd20eff-7cca-4e68-a88a-b3e513e03bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_88e3d64a-a224-4c60-8e48-ba3e28190303" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_ebd20eff-7cca-4e68-a88a-b3e513e03bdd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_9be130f0-6636-42a7-9aa5-40b99906550e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_ebd20eff-7cca-4e68-a88a-b3e513e03bdd" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_9be130f0-6636-42a7-9aa5-40b99906550e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_132f518b-cf01-404e-80cf-0811a23f5d2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_ebd20eff-7cca-4e68-a88a-b3e513e03bdd" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_132f518b-cf01-404e-80cf-0811a23f5d2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_ba80bf72-dd90-40dc-a309-6041915e4036" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_ebd20eff-7cca-4e68-a88a-b3e513e03bdd" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_ba80bf72-dd90-40dc-a309-6041915e4036" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_efc1c14f-9d3e-482e-973d-6f1c775301d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_ebd20eff-7cca-4e68-a88a-b3e513e03bdd" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_efc1c14f-9d3e-482e-973d-6f1c775301d4" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/EmployeeBenefitandDeferredCompensationPlansSummaryoftheChangesinRestrictedStockDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#EmployeeBenefitandDeferredCompensationPlansSummaryoftheChangesinRestrictedStockDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/EmployeeBenefitandDeferredCompensationPlansSummaryoftheChangesinRestrictedStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c90d3aef-9bf6-4696-97fb-2ac218ec4049" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e3993b34-eb42-492a-9a69-a6411327a3df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c90d3aef-9bf6-4696-97fb-2ac218ec4049" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e3993b34-eb42-492a-9a69-a6411327a3df" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_e3d61e82-7e3e-4a41-8aef-f8c61e69928d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e3993b34-eb42-492a-9a69-a6411327a3df" xlink:to="loc_us-gaap_AwardTypeAxis_e3d61e82-7e3e-4a41-8aef-f8c61e69928d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e3d61e82-7e3e-4a41-8aef-f8c61e69928d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_e3d61e82-7e3e-4a41-8aef-f8c61e69928d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e3d61e82-7e3e-4a41-8aef-f8c61e69928d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9aa47542-0fb0-4c45-a3ff-4d427e1b8ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_e3d61e82-7e3e-4a41-8aef-f8c61e69928d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9aa47542-0fb0-4c45-a3ff-4d427e1b8ce7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_6e24d371-52d7-4847-82d5-11206d9bb66f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9aa47542-0fb0-4c45-a3ff-4d427e1b8ce7" xlink:to="loc_us-gaap_PerformanceSharesMember_6e24d371-52d7-4847-82d5-11206d9bb66f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_70dda0f5-cc40-44ea-8699-519072e2ed6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9aa47542-0fb0-4c45-a3ff-4d427e1b8ce7" xlink:to="loc_us-gaap_RestrictedStockMember_70dda0f5-cc40-44ea-8699-519072e2ed6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_1bb72184-89b3-4be3-972f-55be78c6ce3e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e3993b34-eb42-492a-9a69-a6411327a3df" xlink:to="loc_us-gaap_PlanNameAxis_1bb72184-89b3-4be3-972f-55be78c6ce3e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_1bb72184-89b3-4be3-972f-55be78c6ce3e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_1bb72184-89b3-4be3-972f-55be78c6ce3e" xlink:to="loc_us-gaap_PlanNameDomain_1bb72184-89b3-4be3-972f-55be78c6ce3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01013d09-11b4-4ac6-906e-4271f35ffa1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_1bb72184-89b3-4be3-972f-55be78c6ce3e" xlink:to="loc_us-gaap_PlanNameDomain_01013d09-11b4-4ac6-906e-4271f35ffa1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_A2007StockIncentivePlanMember_5ea85c67-02eb-4ea4-9fe9-0fca66a84fdc" xlink:href="rnst-20250930.xsd#rnst_A2007StockIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_01013d09-11b4-4ac6-906e-4271f35ffa1d" xlink:to="loc_rnst_A2007StockIncentivePlanMember_5ea85c67-02eb-4ea4-9fe9-0fca66a84fdc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b75a5871-2da1-45bd-898d-c863e7395125" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c90d3aef-9bf6-4696-97fb-2ac218ec4049" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b75a5871-2da1-45bd-898d-c863e7395125" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_9dbbe97b-6b01-4486-8359-79c1acf768a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b75a5871-2da1-45bd-898d-c863e7395125" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_9dbbe97b-6b01-4486-8359-79c1acf768a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_2be6484b-0b9b-492a-9ec9-88722c466ecf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b75a5871-2da1-45bd-898d-c863e7395125" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_2be6484b-0b9b-492a-9ec9-88722c466ecf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_1795c6f9-23b5-43ae-a75a-0da73c2aa288" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b75a5871-2da1-45bd-898d-c863e7395125" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_1795c6f9-23b5-43ae-a75a-0da73c2aa288" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_389bf74e-ad23-4e84-8ea2-49670aebad67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_b75a5871-2da1-45bd-898d-c863e7395125" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_389bf74e-ad23-4e84-8ea2-49670aebad67" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_01fa30b3-49a3-4d17-9610-fd24fc5f2943" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f184e54f-551c-4a67-91dc-2fa7fba7be1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_c90d3aef-9bf6-4696-97fb-2ac218ec4049" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f184e54f-551c-4a67-91dc-2fa7fba7be1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6509e6f0-e1f0-4b96-af6c-27c08c953519" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f184e54f-551c-4a67-91dc-2fa7fba7be1c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6509e6f0-e1f0-4b96-af6c-27c08c953519" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_487b854f-5984-4a8c-b3bc-0a1dab351399" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f184e54f-551c-4a67-91dc-2fa7fba7be1c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_487b854f-5984-4a8c-b3bc-0a1dab351399" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_2c63aabf-6985-472e-ae46-3b13995dfacf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f184e54f-551c-4a67-91dc-2fa7fba7be1c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_2c63aabf-6985-472e-ae46-3b13995dfacf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_5c4bd0f5-4f93-452b-b999-5afa84208e78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_f184e54f-551c-4a67-91dc-2fa7fba7be1c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_5c4bd0f5-4f93-452b-b999-5afa84208e78" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_5a7ad78d-c845-4832-800b-cf3b7d80185f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/DerivativeInstrumentsScheduleofNotionalandFairValueofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#DerivativeInstrumentsScheduleofNotionalandFairValueofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/DerivativeInstrumentsScheduleofNotionalandFairValueofDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_46adb05a-32c2-41cd-817a-f7d62c0dece6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_46adb05a-32c2-41cd-817a-f7d62c0dece6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_46adb05a-32c2-41cd-817a-f7d62c0dece6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_46adb05a-32c2-41cd-817a-f7d62c0dece6" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_46adb05a-32c2-41cd-817a-f7d62c0dece6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_5da63c78-60be-4a59-8ca0-a8e678f51501" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_46adb05a-32c2-41cd-817a-f7d62c0dece6" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_5da63c78-60be-4a59-8ca0-a8e678f51501" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_19645c3f-f568-4970-90bd-7fe2fa081622" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_5da63c78-60be-4a59-8ca0-a8e678f51501" xlink:to="loc_us-gaap_OtherAssetsMember_19645c3f-f568-4970-90bd-7fe2fa081622" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesMember_2c9c00d0-4f45-4220-b11e-8251abb61caa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_5da63c78-60be-4a59-8ca0-a8e678f51501" xlink:to="loc_us-gaap_OtherLiabilitiesMember_2c9c00d0-4f45-4220-b11e-8251abb61caa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_fc2c4500-4f85-4218-b788-427583065645" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:to="loc_us-gaap_HedgingDesignationAxis_fc2c4500-4f85-4218-b788-427583065645" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_fc2c4500-4f85-4218-b788-427583065645_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_fc2c4500-4f85-4218-b788-427583065645" xlink:to="loc_us-gaap_HedgingDesignationDomain_fc2c4500-4f85-4218-b788-427583065645_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_d2cfd089-d472-4fe6-9c84-daf4ea129cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_fc2c4500-4f85-4218-b788-427583065645" xlink:to="loc_us-gaap_HedgingDesignationDomain_d2cfd089-d472-4fe6-9c84-daf4ea129cb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_e9e8a927-8f47-4ea3-b03f-1298cbc8586a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_d2cfd089-d472-4fe6-9c84-daf4ea129cb2" xlink:to="loc_us-gaap_NondesignatedMember_e9e8a927-8f47-4ea3-b03f-1298cbc8586a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_f9651037-db54-4303-8790-c5d8bdf454db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_d2cfd089-d472-4fe6-9c84-daf4ea129cb2" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_f9651037-db54-4303-8790-c5d8bdf454db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7a59bd-102c-409a-a89c-e6dbbb0a8ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7a59bd-102c-409a-a89c-e6dbbb0a8ac2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_bd7a59bd-102c-409a-a89c-e6dbbb0a8ac2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7a59bd-102c-409a-a89c-e6dbbb0a8ac2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_bd7a59bd-102c-409a-a89c-e6dbbb0a8ac2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7a59bd-102c-409a-a89c-e6dbbb0a8ac2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_4ea2a2f8-0465-458e-bb0d-86bf6af9fefd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:to="loc_us-gaap_InterestRateContractMember_4ea2a2f8-0465-458e-bb0d-86bf6af9fefd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateLockCommitmentsMember_a50e6804-a864-4be6-b61b-d91877bcedd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateLockCommitmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:to="loc_us-gaap_InterestRateLockCommitmentsMember_a50e6804-a864-4be6-b61b-d91877bcedd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForwardContractsMember_9bab7ddc-a0b2-4e99-9f10-5ac16fffb68b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForwardContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:to="loc_us-gaap_ForwardContractsMember_9bab7ddc-a0b2-4e99-9f10-5ac16fffb68b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_24d8a8c1-8e8b-4c0c-a5d9-a69e4ab16fcc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:to="loc_us-gaap_InterestRateSwapMember_24d8a8c1-8e8b-4c0c-a5d9-a69e4ab16fcc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InterestRateCollarMember_adf48712-20f1-434f-98e1-b75aa8bc471f" xlink:href="rnst-20250930.xsd#rnst_InterestRateCollarMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f007c297-b556-4013-be21-ef3360405320" xlink:to="loc_rnst_InterestRateCollarMember_adf48712-20f1-434f-98e1-b75aa8bc471f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_95bfec71-59ce-4eb2-a62a-2dc82ea3d170" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_95bfec71-59ce-4eb2-a62a-2dc82ea3d170" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_95bfec71-59ce-4eb2-a62a-2dc82ea3d170_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_95bfec71-59ce-4eb2-a62a-2dc82ea3d170" xlink:to="loc_us-gaap_HedgingRelationshipDomain_95bfec71-59ce-4eb2-a62a-2dc82ea3d170_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_2498fda0-674d-434a-adb8-aee846e6891b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_95bfec71-59ce-4eb2-a62a-2dc82ea3d170" xlink:to="loc_us-gaap_HedgingRelationshipDomain_2498fda0-674d-434a-adb8-aee846e6891b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_359471d2-729f-4c90-b915-78280842ba48" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_2498fda0-674d-434a-adb8-aee846e6891b" xlink:to="loc_us-gaap_CashFlowHedgingMember_359471d2-729f-4c90-b915-78280842ba48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_a2124d95-7d04-4d87-8298-f0c62af5401b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_2498fda0-674d-434a-adb8-aee846e6891b" xlink:to="loc_us-gaap_FairValueHedgingMember_a2124d95-7d04-4d87-8298-f0c62af5401b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_b56c1e7f-17e7-4669-a52f-c89813c53361" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_196934f4-29cf-454f-9e69-8fc0026a556c" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_b56c1e7f-17e7-4669-a52f-c89813c53361" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_b56c1e7f-17e7-4669-a52f-c89813c53361_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_b56c1e7f-17e7-4669-a52f-c89813c53361" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_b56c1e7f-17e7-4669-a52f-c89813c53361_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ec98c492-53ac-46c4-827d-b06aa353d1d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_b56c1e7f-17e7-4669-a52f-c89813c53361" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ec98c492-53ac-46c4-827d-b06aa353d1d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebtMember_149f9e27-6d52-44cf-8bdf-311c1b95c7cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ec98c492-53ac-46c4-827d-b06aa353d1d5" xlink:to="loc_us-gaap_SubordinatedDebtMember_149f9e27-6d52-44cf-8bdf-311c1b95c7cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_SecuritiesMember_cae4f969-9d86-4107-bb00-1080c4810db7" xlink:href="rnst-20250930.xsd#rnst_SecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ec98c492-53ac-46c4-827d-b06aa353d1d5" xlink:to="loc_rnst_SecuritiesMember_cae4f969-9d86-4107-bb00-1080c4810db7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_8f140bd3-0f17-42c6-80e9-852fdaab11de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_8f140bd3-0f17-42c6-80e9-852fdaab11de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_bb2d19d4-7164-4f5f-bd7c-4638ce4f33ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_bb2d19d4-7164-4f5f-bd7c-4638ce4f33ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_2b65c29f-a81b-4136-a117-f021feb009d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_2b65c29f-a81b-4136-a117-f021feb009d4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_5ddb67d9-c477-4cf1-ade6-f7b84d82d144" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_5ddb67d9-c477-4cf1-ade6-f7b84d82d144" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_a26e2740-1adf-449b-9957-1c9a330b43bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_a26e2740-1adf-449b-9957-1c9a330b43bd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_9fb82e82-ccb9-43da-8612-b995f9c3e38a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_0d8a1da4-d823-4678-8967-08fc70672156" xlink:to="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_9fb82e82-ccb9-43da-8612-b995f9c3e38a" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/DerivativeInstrumentsGainsLossesofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#DerivativeInstrumentsGainsLossesofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/DerivativeInstrumentsGainsLossesofDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_679ed758-66c6-49d4-9159-e337bb262737" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_fc57d47e-4c8e-4d2c-91ee-a61bebff1763" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_679ed758-66c6-49d4-9159-e337bb262737" xlink:to="loc_us-gaap_DerivativeTable_fc57d47e-4c8e-4d2c-91ee-a61bebff1763" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_06463037-70a7-4a1c-b37f-530a039e423c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_fc57d47e-4c8e-4d2c-91ee-a61bebff1763" xlink:to="loc_us-gaap_HedgingDesignationAxis_06463037-70a7-4a1c-b37f-530a039e423c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_06463037-70a7-4a1c-b37f-530a039e423c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_06463037-70a7-4a1c-b37f-530a039e423c" xlink:to="loc_us-gaap_HedgingDesignationDomain_06463037-70a7-4a1c-b37f-530a039e423c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_14fd5d0a-823a-4c54-bc87-18f5b1cb9614" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_06463037-70a7-4a1c-b37f-530a039e423c" xlink:to="loc_us-gaap_HedgingDesignationDomain_14fd5d0a-823a-4c54-bc87-18f5b1cb9614" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_5e13d4c1-7423-4e75-97c2-18a1a6cbb815" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_14fd5d0a-823a-4c54-bc87-18f5b1cb9614" xlink:to="loc_us-gaap_NondesignatedMember_5e13d4c1-7423-4e75-97c2-18a1a6cbb815" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_ac39c3d9-663a-4111-8a10-b4b88c81a429" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_fc57d47e-4c8e-4d2c-91ee-a61bebff1763" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_ac39c3d9-663a-4111-8a10-b4b88c81a429" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_ac39c3d9-663a-4111-8a10-b4b88c81a429_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_ac39c3d9-663a-4111-8a10-b4b88c81a429" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_ac39c3d9-663a-4111-8a10-b4b88c81a429_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1f5e1aa1-3bf7-4758-a3a3-f3eab4c9d40b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_ac39c3d9-663a-4111-8a10-b4b88c81a429" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1f5e1aa1-3bf7-4758-a3a3-f3eab4c9d40b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_0c89b4d7-30f8-488f-8367-8eb212660a3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1f5e1aa1-3bf7-4758-a3a3-f3eab4c9d40b" xlink:to="loc_us-gaap_InterestRateContractMember_0c89b4d7-30f8-488f-8367-8eb212660a3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateLockCommitmentsMember_2faea0a1-09e8-4331-97aa-a200efd3ce2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateLockCommitmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1f5e1aa1-3bf7-4758-a3a3-f3eab4c9d40b" xlink:to="loc_us-gaap_InterestRateLockCommitmentsMember_2faea0a1-09e8-4331-97aa-a200efd3ce2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForwardContractsMember_52d9dc83-1f5d-4087-8d3e-32f593310fde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForwardContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1f5e1aa1-3bf7-4758-a3a3-f3eab4c9d40b" xlink:to="loc_us-gaap_ForwardContractsMember_52d9dc83-1f5d-4087-8d3e-32f593310fde" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNetAbstract_79036714-8617-46b8-b0d4-710a3e1c8161" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeGainLossOnDerivativeNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_679ed758-66c6-49d4-9159-e337bb262737" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNetAbstract_79036714-8617-46b8-b0d4-710a3e1c8161" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_9a9b5154-76df-4b8a-8383-f165b5f6f6ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeGainLossOnDerivativeNetAbstract_79036714-8617-46b8-b0d4-710a3e1c8161" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_9a9b5154-76df-4b8a-8383-f165b5f6f6ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_6ef14006-9808-44b0-81ba-9217ca9654c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_679ed758-66c6-49d4-9159-e337bb262737" xlink:to="loc_us-gaap_DerivativeGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_6ef14006-9808-44b0-81ba-9217ca9654c8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/DerivativeInstrumentsFairValueHedgeImpactonStatementofIncomeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#DerivativeInstrumentsFairValueHedgeImpactonStatementofIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/DerivativeInstrumentsFairValueHedgeImpactonStatementofIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_bf974c94-ecb8-43b8-9b89-635af16bb80a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_bd8229e8-8ab8-4c91-849d-efaef90e2e86" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_bf974c94-ecb8-43b8-9b89-635af16bb80a" xlink:to="loc_us-gaap_DerivativeTable_bd8229e8-8ab8-4c91-849d-efaef90e2e86" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_0a5a75b1-9869-46f6-9f4e-c785d72ed1a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bd8229e8-8ab8-4c91-849d-efaef90e2e86" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_0a5a75b1-9869-46f6-9f4e-c785d72ed1a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_0a5a75b1-9869-46f6-9f4e-c785d72ed1a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_0a5a75b1-9869-46f6-9f4e-c785d72ed1a1" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_0a5a75b1-9869-46f6-9f4e-c785d72ed1a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_c54b3b5f-6c5f-4b51-9930-a4d26c79417d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_0a5a75b1-9869-46f6-9f4e-c785d72ed1a1" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_c54b3b5f-6c5f-4b51-9930-a4d26c79417d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_2b965f5b-8a6b-46fe-999a-324ad029c124" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_c54b3b5f-6c5f-4b51-9930-a4d26c79417d" xlink:to="loc_us-gaap_InterestRateSwapMember_2b965f5b-8a6b-46fe-999a-324ad029c124" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_cd3db5dd-3e23-486b-9d7a-4b24d6634344" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bd8229e8-8ab8-4c91-849d-efaef90e2e86" xlink:to="loc_us-gaap_HedgingDesignationAxis_cd3db5dd-3e23-486b-9d7a-4b24d6634344" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_cd3db5dd-3e23-486b-9d7a-4b24d6634344_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_cd3db5dd-3e23-486b-9d7a-4b24d6634344" xlink:to="loc_us-gaap_HedgingDesignationDomain_cd3db5dd-3e23-486b-9d7a-4b24d6634344_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_1fa48c3d-69b2-496f-a71a-67743e86e738" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_cd3db5dd-3e23-486b-9d7a-4b24d6634344" xlink:to="loc_us-gaap_HedgingDesignationDomain_1fa48c3d-69b2-496f-a71a-67743e86e738" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2f2cb406-cb03-4876-b274-28cdb79425e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_1fa48c3d-69b2-496f-a71a-67743e86e738" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2f2cb406-cb03-4876-b274-28cdb79425e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_e1189d2c-4123-4143-8d0b-59c6bbfa1f8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bd8229e8-8ab8-4c91-849d-efaef90e2e86" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_e1189d2c-4123-4143-8d0b-59c6bbfa1f8b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_e1189d2c-4123-4143-8d0b-59c6bbfa1f8b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_e1189d2c-4123-4143-8d0b-59c6bbfa1f8b" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_e1189d2c-4123-4143-8d0b-59c6bbfa1f8b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_f90c53c5-c446-4daa-b90f-2bf6edbecd53" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_e1189d2c-4123-4143-8d0b-59c6bbfa1f8b" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_f90c53c5-c446-4daa-b90f-2bf6edbecd53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseMember_b29f99e5-b5bf-493a-8b9d-c5b5d369ca89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f90c53c5-c446-4daa-b90f-2bf6edbecd53" xlink:to="loc_us-gaap_InterestExpenseMember_b29f99e5-b5bf-493a-8b9d-c5b5d369ca89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeMember_6ae2d43c-914d-4983-b6c6-13198c799289" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f90c53c5-c446-4daa-b90f-2bf6edbecd53" xlink:to="loc_us-gaap_InterestIncomeMember_6ae2d43c-914d-4983-b6c6-13198c799289" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_36cfdde6-9ab3-45a0-a174-3cc423a180fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bd8229e8-8ab8-4c91-849d-efaef90e2e86" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_36cfdde6-9ab3-45a0-a174-3cc423a180fe" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_36cfdde6-9ab3-45a0-a174-3cc423a180fe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_36cfdde6-9ab3-45a0-a174-3cc423a180fe" xlink:to="loc_us-gaap_HedgingRelationshipDomain_36cfdde6-9ab3-45a0-a174-3cc423a180fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_cd6bedfb-758c-4ffe-ae7d-8cf094ecd35b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_36cfdde6-9ab3-45a0-a174-3cc423a180fe" xlink:to="loc_us-gaap_HedgingRelationshipDomain_cd6bedfb-758c-4ffe-ae7d-8cf094ecd35b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_0474564b-6c40-44ba-b86a-c829d2f26d92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_cd6bedfb-758c-4ffe-ae7d-8cf094ecd35b" xlink:to="loc_us-gaap_FairValueHedgingMember_0474564b-6c40-44ba-b86a-c829d2f26d92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_3c3a24a2-0a74-44c0-b962-ea468195f522" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_bf974c94-ecb8-43b8-9b89-635af16bb80a" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_3c3a24a2-0a74-44c0-b962-ea468195f522" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_3f0c6c79-8c29-427f-8ec5-78cfb57b43d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_bf974c94-ecb8-43b8-9b89-635af16bb80a" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_3f0c6c79-8c29-427f-8ec5-78cfb57b43d2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/DerivativeInstrumentsFairValueHedgeImpactonBalanceSheetDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#DerivativeInstrumentsFairValueHedgeImpactonBalanceSheetDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/DerivativeInstrumentsFairValueHedgeImpactonBalanceSheetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_515fa8bc-c0a9-47ea-8d68-3e9341678a4d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_77580d1e-f8ea-4ae3-aac5-0a57640abb91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_515fa8bc-c0a9-47ea-8d68-3e9341678a4d" xlink:to="loc_us-gaap_DerivativeTable_77580d1e-f8ea-4ae3-aac5-0a57640abb91" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_d790c343-614e-48f1-9614-be8f139da5c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_77580d1e-f8ea-4ae3-aac5-0a57640abb91" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_d790c343-614e-48f1-9614-be8f139da5c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_d790c343-614e-48f1-9614-be8f139da5c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_d790c343-614e-48f1-9614-be8f139da5c1" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_d790c343-614e-48f1-9614-be8f139da5c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_6f6336ce-9da0-42b0-83d9-31d6d57a2844" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_d790c343-614e-48f1-9614-be8f139da5c1" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_6f6336ce-9da0-42b0-83d9-31d6d57a2844" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMember_8ebbb4d4-8b1b-4c5c-9ad7-82f6d5e24576" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_6f6336ce-9da0-42b0-83d9-31d6d57a2844" xlink:to="loc_us-gaap_LongTermDebtMember_8ebbb4d4-8b1b-4c5c-9ad7-82f6d5e24576" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_dc674550-ff33-46f3-a315-27a613f6a5f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_77580d1e-f8ea-4ae3-aac5-0a57640abb91" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_dc674550-ff33-46f3-a315-27a613f6a5f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_dc674550-ff33-46f3-a315-27a613f6a5f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_dc674550-ff33-46f3-a315-27a613f6a5f6" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_dc674550-ff33-46f3-a315-27a613f6a5f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_85f6984b-dc4d-403f-8cb7-d88fe5f4eaaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_dc674550-ff33-46f3-a315-27a613f6a5f6" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_85f6984b-dc4d-403f-8cb7-d88fe5f4eaaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesAvailableForSaleMember_59aa0de2-7e89-439a-b09f-49aebf8ea8e1" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesAvailableForSaleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_85f6984b-dc4d-403f-8cb7-d88fe5f4eaaa" xlink:to="loc_rnst_DebtSecuritiesAvailableForSaleMember_59aa0de2-7e89-439a-b09f-49aebf8ea8e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgedLiabilityFairValueHedge_802d3523-e44e-4367-a9d8-e72cbcafbaf2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgedLiabilityFairValueHedge"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_515fa8bc-c0a9-47ea-8d68-3e9341678a4d" xlink:to="loc_us-gaap_HedgedLiabilityFairValueHedge_802d3523-e44e-4367-a9d8-e72cbcafbaf2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease_4944788c-8ed1-42d6-baca-ba2fd6843624" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_515fa8bc-c0a9-47ea-8d68-3e9341678a4d" xlink:to="loc_us-gaap_HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease_4944788c-8ed1-42d6-baca-ba2fd6843624" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/DerivativeInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#DerivativeInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/DerivativeInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_db7942f7-7de4-4689-ae82-55acb2fc017a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_08be39bb-e4ba-440a-86ce-9c73ad98914e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_db7942f7-7de4-4689-ae82-55acb2fc017a" xlink:to="loc_us-gaap_DerivativeTable_08be39bb-e4ba-440a-86ce-9c73ad98914e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_dc0b3287-c1d9-477a-82fa-b0aabbff628f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_08be39bb-e4ba-440a-86ce-9c73ad98914e" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_dc0b3287-c1d9-477a-82fa-b0aabbff628f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_dc0b3287-c1d9-477a-82fa-b0aabbff628f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_dc0b3287-c1d9-477a-82fa-b0aabbff628f" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_dc0b3287-c1d9-477a-82fa-b0aabbff628f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_a26ae7ea-6e7f-4a8f-97e8-27a236daf0b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_dc0b3287-c1d9-477a-82fa-b0aabbff628f" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_a26ae7ea-6e7f-4a8f-97e8-27a236daf0b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_RiskParticipationAgreementMember_f662e40b-8402-4b98-b048-4032e477790f" xlink:href="rnst-20250930.xsd#rnst_RiskParticipationAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a26ae7ea-6e7f-4a8f-97e8-27a236daf0b1" xlink:to="loc_rnst_RiskParticipationAgreementMember_f662e40b-8402-4b98-b048-4032e477790f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_da3433af-f5d9-4f0e-aa3c-1914640406e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditDerivativeMaximumExposureUndiscounted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_db7942f7-7de4-4689-ae82-55acb2fc017a" xlink:to="loc_us-gaap_CreditDerivativeMaximumExposureUndiscounted_da3433af-f5d9-4f0e-aa3c-1914640406e4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_66a83a38-b8d6-4c70-ac34-6f8a96f081fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_a7841444-818d-4743-9211-642db5dd303a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_66a83a38-b8d6-4c70-ac34-6f8a96f081fd" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_a7841444-818d-4743-9211-642db5dd303a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4e83a0d2-fe62-4ac5-a261-655c5e7bff1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_a7841444-818d-4743-9211-642db5dd303a" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4e83a0d2-fe62-4ac5-a261-655c5e7bff1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_4e83a0d2-fe62-4ac5-a261-655c5e7bff1c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4e83a0d2-fe62-4ac5-a261-655c5e7bff1c" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_4e83a0d2-fe62-4ac5-a261-655c5e7bff1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_1de4666c-997b-43c9-822b-c688efb42781" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4e83a0d2-fe62-4ac5-a261-655c5e7bff1c" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_1de4666c-997b-43c9-822b-c688efb42781" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_a6612f74-ee1a-4ec0-b820-29c65b342e11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_1de4666c-997b-43c9-822b-c688efb42781" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_a6612f74-ee1a-4ec0-b820-29c65b342e11" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d6db940-35a7-4620-bee5-e597acdb6c8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_a7841444-818d-4743-9211-642db5dd303a" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d6db940-35a7-4620-bee5-e597acdb6c8f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1d6db940-35a7-4620-bee5-e597acdb6c8f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d6db940-35a7-4620-bee5-e597acdb6c8f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1d6db940-35a7-4620-bee5-e597acdb6c8f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f6233a-a342-4b9a-a44e-2d81f3289c90" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d6db940-35a7-4620-bee5-e597acdb6c8f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f6233a-a342-4b9a-a44e-2d81f3289c90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_cff703f3-20bb-4789-b2f9-22d4f92a293f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f6233a-a342-4b9a-a44e-2d81f3289c90" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_cff703f3-20bb-4789-b2f9-22d4f92a293f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_1cbc6600-1daa-4fa9-98bc-b7f5f2317674" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f6233a-a342-4b9a-a44e-2d81f3289c90" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_1cbc6600-1daa-4fa9-98bc-b7f5f2317674" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_833d4063-2ea1-4b07-983b-e8ff691a235c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59f6233a-a342-4b9a-a44e-2d81f3289c90" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_833d4063-2ea1-4b07-983b-e8ff691a235c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_42d2295f-9247-4d32-b036-62b753ccf78a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_a7841444-818d-4743-9211-642db5dd303a" xlink:to="loc_us-gaap_FinancialInstrumentAxis_42d2295f-9247-4d32-b036-62b753ccf78a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_42d2295f-9247-4d32-b036-62b753ccf78a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_42d2295f-9247-4d32-b036-62b753ccf78a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_42d2295f-9247-4d32-b036-62b753ccf78a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_36964913-8ce8-4f8e-af02-518ca617243d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_42d2295f-9247-4d32-b036-62b753ccf78a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_36964913-8ce8-4f8e-af02-518ca617243d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_DebtSecuritiesAvailableforSaleOtherMember_0644e9f9-4821-4145-a3bd-c91ada8bb39c" xlink:href="rnst-20250930.xsd#rnst_DebtSecuritiesAvailableforSaleOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_36964913-8ce8-4f8e-af02-518ca617243d" xlink:to="loc_rnst_DebtSecuritiesAvailableforSaleOtherMember_0644e9f9-4821-4145-a3bd-c91ada8bb39c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_3b8c4b88-e890-4478-906c-17f1e9d1cf38" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_66a83a38-b8d6-4c70-ac34-6f8a96f081fd" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_3b8c4b88-e890-4478-906c-17f1e9d1cf38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_51dc379f-6b3f-4e0f-ae9e-9602521f0e84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_3b8c4b88-e890-4478-906c-17f1e9d1cf38" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_51dc379f-6b3f-4e0f-ae9e-9602521f0e84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_33d3690e-75be-4ed5-ab60-62eae2cd562a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_51dc379f-6b3f-4e0f-ae9e-9602521f0e84" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_33d3690e-75be-4ed5-ab60-62eae2cd562a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_1cceef60-aa26-4b4d-8d9d-46b544b508a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_51dc379f-6b3f-4e0f-ae9e-9602521f0e84" xlink:to="loc_us-gaap_DerivativeAssets_1cceef60-aa26-4b4d-8d9d-46b544b508a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgagesHeldForSaleFairValueDisclosure_eb8e34ed-126c-4718-b927-374cc3771d66" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MortgagesHeldForSaleFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_51dc379f-6b3f-4e0f-ae9e-9602521f0e84" xlink:to="loc_us-gaap_MortgagesHeldForSaleFairValueDisclosure_eb8e34ed-126c-4718-b927-374cc3771d66" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_93b1d400-2cd0-4305-b425-24c11f766790" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_51dc379f-6b3f-4e0f-ae9e-9602521f0e84" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_93b1d400-2cd0-4305-b425-24c11f766790" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9126d452-a01d-4126-8bb3-930196a620c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_3b8c4b88-e890-4478-906c-17f1e9d1cf38" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9126d452-a01d-4126-8bb3-930196a620c3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_82a34427-7057-4f98-a91f-b72b434559f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_9126d452-a01d-4126-8bb3-930196a620c3" xlink:to="loc_us-gaap_DerivativeLiabilities_82a34427-7057-4f98-a91f-b72b434559f9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsAssetsMeasuredatFairValueonaNonrecurringBasisDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsAssetsMeasuredatFairValueonaNonrecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsAssetsMeasuredatFairValueonaNonrecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ed84f34d-3e55-4913-b141-2fd253c3501f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88d1116f-cac4-4888-acc4-ae200ffc1da0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ed84f34d-3e55-4913-b141-2fd253c3501f" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88d1116f-cac4-4888-acc4-ae200ffc1da0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_aadaf0d8-8f82-46a1-8795-a7e191279ecf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88d1116f-cac4-4888-acc4-ae200ffc1da0" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_aadaf0d8-8f82-46a1-8795-a7e191279ecf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_aadaf0d8-8f82-46a1-8795-a7e191279ecf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_aadaf0d8-8f82-46a1-8795-a7e191279ecf" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_aadaf0d8-8f82-46a1-8795-a7e191279ecf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_e1094a91-e608-4113-a574-6239d088d766" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_aadaf0d8-8f82-46a1-8795-a7e191279ecf" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_e1094a91-e608-4113-a574-6239d088d766" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_68da8ae0-0788-48a9-9ef0-d2429b818f61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsNonrecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_e1094a91-e608-4113-a574-6239d088d766" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_68da8ae0-0788-48a9-9ef0-d2429b818f61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5f66940f-f66c-4486-80f4-c6ac43f13581" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_88d1116f-cac4-4888-acc4-ae200ffc1da0" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5f66940f-f66c-4486-80f4-c6ac43f13581" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f66940f-f66c-4486-80f4-c6ac43f13581_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5f66940f-f66c-4486-80f4-c6ac43f13581" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5f66940f-f66c-4486-80f4-c6ac43f13581_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_41c5ccfe-b033-4506-bc09-52141a821412" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_5f66940f-f66c-4486-80f4-c6ac43f13581" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_41c5ccfe-b033-4506-bc09-52141a821412" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_ba2346e6-98d5-4fd6-b0b5-e067b03571fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_41c5ccfe-b033-4506-bc09-52141a821412" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_ba2346e6-98d5-4fd6-b0b5-e067b03571fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_214a95ad-90d9-406e-851f-7ffc6dc9db62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_41c5ccfe-b033-4506-bc09-52141a821412" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_214a95ad-90d9-406e-851f-7ffc6dc9db62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_211b2f0e-7073-4eb5-ba97-c7ddd6584161" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_41c5ccfe-b033-4506-bc09-52141a821412" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_211b2f0e-7073-4eb5-ba97-c7ddd6584161" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FairValueMeasurementOnImpairedLoansOnNonRecurringBasisAbstract_7becebd6-7d62-49d8-8a60-c9c387f4a540" xlink:href="rnst-20250930.xsd#rnst_FairValueMeasurementOnImpairedLoansOnNonRecurringBasisAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_ed84f34d-3e55-4913-b141-2fd253c3501f" xlink:to="loc_rnst_FairValueMeasurementOnImpairedLoansOnNonRecurringBasisAbstract_7becebd6-7d62-49d8-8a60-c9c387f4a540" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis_8552167b-85d6-4f60-aa4a-7f85e1696c3a" xlink:href="rnst-20250930.xsd#rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_FairValueMeasurementOnImpairedLoansOnNonRecurringBasisAbstract_7becebd6-7d62-49d8-8a60-c9c387f4a540" xlink:to="loc_rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis_8552167b-85d6-4f60-aa4a-7f85e1696c3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonRecurringBasis_9e539ec9-dc57-4ead-9cdd-3c749923fbd0" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonRecurringBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_FairValueMeasurementOnImpairedLoansOnNonRecurringBasisAbstract_7becebd6-7d62-49d8-8a60-c9c387f4a540" xlink:to="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonRecurringBasis_9e539ec9-dc57-4ead-9cdd-3c749923fbd0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_1d00e601-3cab-4cee-b742-db122e948c41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_FairValueMeasurementOnImpairedLoansOnNonRecurringBasisAbstract_7becebd6-7d62-49d8-8a60-c9c387f4a540" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_1d00e601-3cab-4cee-b742-db122e948c41" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b1c86754-729a-4378-b035-fabf23553846" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8d34cd3e-5f2e-4fa7-9bd6-6c3fa7781643" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b1c86754-729a-4378-b035-fabf23553846" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8d34cd3e-5f2e-4fa7-9bd6-6c3fa7781643" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a2aeb52e-3472-4885-8404-885cf79827ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_8d34cd3e-5f2e-4fa7-9bd6-6c3fa7781643" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a2aeb52e-3472-4885-8404-885cf79827ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_a2aeb52e-3472-4885-8404-885cf79827ad_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a2aeb52e-3472-4885-8404-885cf79827ad" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_a2aeb52e-3472-4885-8404-885cf79827ad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_1e6c3bdd-bac8-4216-a7b9-58fa1948c466" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_a2aeb52e-3472-4885-8404-885cf79827ad" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_1e6c3bdd-bac8-4216-a7b9-58fa1948c466" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ImpairedLoansNotCoveredMember_751255e1-55a4-49d2-96b7-4ad7c28471d6" xlink:href="rnst-20250930.xsd#rnst_ImpairedLoansNotCoveredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_1e6c3bdd-bac8-4216-a7b9-58fa1948c466" xlink:to="loc_rnst_ImpairedLoansNotCoveredMember_751255e1-55a4-49d2-96b7-4ad7c28471d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ContractualBalanceImpairedLoansMeasuredAtFairValueOnNonrecurringBasis_faeef4ee-ef67-4d77-8589-abbeb3cf5a5e" xlink:href="rnst-20250930.xsd#rnst_ContractualBalanceImpairedLoansMeasuredAtFairValueOnNonrecurringBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b1c86754-729a-4378-b035-fabf23553846" xlink:to="loc_rnst_ContractualBalanceImpairedLoansMeasuredAtFairValueOnNonrecurringBasis_faeef4ee-ef67-4d77-8589-abbeb3cf5a5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_6314fec7-e8fb-43d4-9145-168d429fa7d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b1c86754-729a-4378-b035-fabf23553846" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_6314fec7-e8fb-43d4-9145-168d429fa7d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageServicingRightsMSRImpairmentRecovery_268af2b1-62f6-420b-8787-9ecc228e1513" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MortgageServicingRightsMSRImpairmentRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b1c86754-729a-4378-b035-fabf23553846" xlink:to="loc_us-gaap_MortgageServicingRightsMSRImpairmentRecovery_268af2b1-62f6-420b-8787-9ecc228e1513" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueOptionChangesInFairValueGainLoss1_d0d2f0da-c340-473f-9e95-dd32f5470c3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueOptionChangesInFairValueGainLoss1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_b1c86754-729a-4378-b035-fabf23553846" xlink:to="loc_us-gaap_FairValueOptionChangesInFairValueGainLoss1_d0d2f0da-c340-473f-9e95-dd32f5470c3a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsOREOMeasuredatFairValueonaNonrecurringBasisDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsOREOMeasuredatFairValueonaNonrecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsOREOMeasuredatFairValueonaNonrecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisLineItems_6dc54df8-685c-4c85-984e-ac7bf5192d31" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisTable_6d20b3ff-4a69-43a2-b780-c2226cffe08a" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisLineItems_6dc54df8-685c-4c85-984e-ac7bf5192d31" xlink:to="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisTable_6d20b3ff-4a69-43a2-b780-c2226cffe08a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0ddab840-0c52-41a4-b130-e771c980203d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisTable_6d20b3ff-4a69-43a2-b780-c2226cffe08a" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0ddab840-0c52-41a4-b130-e771c980203d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0ddab840-0c52-41a4-b130-e771c980203d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0ddab840-0c52-41a4-b130-e771c980203d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0ddab840-0c52-41a4-b130-e771c980203d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8fffe6fd-0a31-4a7b-b481-090ac038598b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0ddab840-0c52-41a4-b130-e771c980203d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8fffe6fd-0a31-4a7b-b481-090ac038598b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_82fbe1a7-8348-4382-af8a-b61ff87c5699" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8fffe6fd-0a31-4a7b-b481-090ac038598b" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_82fbe1a7-8348-4382-af8a-b61ff87c5699" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0d34b64a-4803-49bf-8c33-2f472da38a26" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisTable_6d20b3ff-4a69-43a2-b780-c2226cffe08a" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0d34b64a-4803-49bf-8c33-2f472da38a26" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_0d34b64a-4803-49bf-8c33-2f472da38a26_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0d34b64a-4803-49bf-8c33-2f472da38a26" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_0d34b64a-4803-49bf-8c33-2f472da38a26_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_33ed6ab2-e0db-4de8-ad3e-b0273a9facbc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0d34b64a-4803-49bf-8c33-2f472da38a26" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_33ed6ab2-e0db-4de8-ad3e-b0273a9facbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_9972d1ad-e2cf-4e42-b1f7-9c4e3af89d8e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsNonrecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_33ed6ab2-e0db-4de8-ad3e-b0273a9facbc" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_9972d1ad-e2cf-4e42-b1f7-9c4e3af89d8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisAbstract_a7c452eb-9fbd-4623-9cb2-a098d64f633f" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisLineItems_6dc54df8-685c-4c85-984e-ac7bf5192d31" xlink:to="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisAbstract_a7c452eb-9fbd-4623-9cb2-a098d64f633f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateNonCoveredCarryingAmount_6894c014-d06e-4476-bbe5-758bcc4a35a8" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateNonCoveredCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisAbstract_a7c452eb-9fbd-4623-9cb2-a098d64f633f" xlink:to="loc_rnst_OtherRealEstateNonCoveredCarryingAmount_6894c014-d06e-4476-bbe5-758bcc4a35a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateNonCoveredImpairmentRecognized_bef2dbc7-f145-44b1-9413-b872abfadf8c" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateNonCoveredImpairmentRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisAbstract_a7c452eb-9fbd-4623-9cb2-a098d64f633f" xlink:to="loc_rnst_OtherRealEstateNonCoveredImpairmentRecognized_bef2dbc7-f145-44b1-9413-b872abfadf8c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OtherRealEstateOwnedNonCoveredFairValue_f5e2e402-5840-4733-9520-cdfd9af07f41" xlink:href="rnst-20250930.xsd#rnst_OtherRealEstateOwnedNonCoveredFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_OtherRealEstateOwnedMeasuredAtFairValueOnNonrecurringBasisAbstract_a7c452eb-9fbd-4623-9cb2-a098d64f633f" xlink:to="loc_rnst_OtherRealEstateOwnedNonCoveredFairValue_f5e2e402-5840-4733-9520-cdfd9af07f41" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsSignificantUnobservableInputsLevel3UsedinValuationofAssetsandLiabilitiesMeasuredatFairValueonNonRecurringBasisDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsSignificantUnobservableInputsLevel3UsedinValuationofAssetsandLiabilitiesMeasuredatFairValueonNonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsSignificantUnobservableInputsLevel3UsedinValuationofAssetsandLiabilitiesMeasuredatFairValueonNonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems_6be794c7-94d4-4e5b-9c09-bfeeff80ede0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable_a63ed60e-fabe-4b36-b7b2-cf0849ccba4b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems_6be794c7-94d4-4e5b-9c09-bfeeff80ede0" xlink:to="loc_us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable_a63ed60e-fabe-4b36-b7b2-cf0849ccba4b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e9bae293-beb4-4640-b7e7-90d7dc513688" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable_a63ed60e-fabe-4b36-b7b2-cf0849ccba4b" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e9bae293-beb4-4640-b7e7-90d7dc513688" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e9bae293-beb4-4640-b7e7-90d7dc513688_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e9bae293-beb4-4640-b7e7-90d7dc513688" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e9bae293-beb4-4640-b7e7-90d7dc513688_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8d94003f-451a-4726-b972-ee35850a6236" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e9bae293-beb4-4640-b7e7-90d7dc513688" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8d94003f-451a-4726-b972-ee35850a6236" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_cbb04d9c-b1f6-4610-928f-2efab5204f20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8d94003f-451a-4726-b972-ee35850a6236" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_cbb04d9c-b1f6-4610-928f-2efab5204f20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_5c792b6a-fd46-41cb-8e2f-20d32b7f1238" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable_a63ed60e-fabe-4b36-b7b2-cf0849ccba4b" xlink:to="loc_us-gaap_FinancialInstrumentAxis_5c792b6a-fd46-41cb-8e2f-20d32b7f1238" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_5c792b6a-fd46-41cb-8e2f-20d32b7f1238_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_5c792b6a-fd46-41cb-8e2f-20d32b7f1238" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_5c792b6a-fd46-41cb-8e2f-20d32b7f1238_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a2ae1726-cd1f-4abf-a254-7e8cc3aa5677" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_5c792b6a-fd46-41cb-8e2f-20d32b7f1238" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a2ae1726-cd1f-4abf-a254-7e8cc3aa5677" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ImpairedLoansMember_dfc4a064-787e-4ce8-968b-1e2277c3c804" xlink:href="rnst-20250930.xsd#rnst_ImpairedLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a2ae1726-cd1f-4abf-a254-7e8cc3aa5677" xlink:to="loc_rnst_ImpairedLoansMember_dfc4a064-787e-4ce8-968b-1e2277c3c804" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_OreoMember_060ed778-3930-4d02-a901-1eadca4dc805" xlink:href="rnst-20250930.xsd#rnst_OreoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a2ae1726-cd1f-4abf-a254-7e8cc3aa5677" xlink:to="loc_rnst_OreoMember_060ed778-3930-4d02-a901-1eadca4dc805" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_6e2b0270-601e-4436-a031-b37038385480" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable_a63ed60e-fabe-4b36-b7b2-cf0849ccba4b" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_6e2b0270-601e-4436-a031-b37038385480" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_6e2b0270-601e-4436-a031-b37038385480_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_6e2b0270-601e-4436-a031-b37038385480" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_6e2b0270-601e-4436-a031-b37038385480_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_584569dc-224a-487c-916a-c570809bfecd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_6e2b0270-601e-4436-a031-b37038385480" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_584569dc-224a-487c-916a-c570809bfecd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPriceVolatilityMember_96f673f3-c39e-4149-9551-f4d66a105203" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_584569dc-224a-487c-916a-c570809bfecd" xlink:to="loc_us-gaap_MeasurementInputPriceVolatilityMember_96f673f3-c39e-4149-9551-f4d66a105203" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_a479c3b2-f36e-4aa0-a466-10bcb57077fa" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable_a63ed60e-fabe-4b36-b7b2-cf0849ccba4b" xlink:to="loc_srt_RangeAxis_a479c3b2-f36e-4aa0-a466-10bcb57077fa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_a479c3b2-f36e-4aa0-a466-10bcb57077fa_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_a479c3b2-f36e-4aa0-a466-10bcb57077fa" xlink:to="loc_srt_RangeMember_a479c3b2-f36e-4aa0-a466-10bcb57077fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ebac0253-b6f4-4854-a2c1-0cbbdf8de48f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_a479c3b2-f36e-4aa0-a466-10bcb57077fa" xlink:to="loc_srt_RangeMember_ebac0253-b6f4-4854-a2c1-0cbbdf8de48f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_d6999866-55d8-431d-bb76-705e7a2cd975" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ebac0253-b6f4-4854-a2c1-0cbbdf8de48f" xlink:to="loc_srt_MinimumMember_d6999866-55d8-431d-bb76-705e7a2cd975" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_988e368d-1725-4eb9-8aa2-3293fb7c61af" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ebac0253-b6f4-4854-a2c1-0cbbdf8de48f" xlink:to="loc_srt_MaximumMember_988e368d-1725-4eb9-8aa2-3293fb7c61af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_29fab7e1-0f4a-4e94-abf3-0ec2d093e870" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems_6be794c7-94d4-4e5b-9c09-bfeeff80ede0" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_29fab7e1-0f4a-4e94-abf3-0ec2d093e870" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis_67aad1b5-73df-42b8-be53-84351c4956a6" xlink:href="rnst-20250930.xsd#rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_29fab7e1-0f4a-4e94-abf3-0ec2d093e870" xlink:to="loc_rnst_ImpairedLoansMeasuredAtFairValueOnNonrecurringBasis_67aad1b5-73df-42b8-be53-84351c4956a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMeasurementInput_5aa78bcd-3ec1-4fc3-8f82-4930388955d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_29fab7e1-0f4a-4e94-abf3-0ec2d093e870" xlink:to="loc_us-gaap_DebtInstrumentMeasurementInput_5aa78bcd-3ec1-4fc3-8f82-4930388955d5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRealEstateOwnedMeasurementInput_212d5976-2db6-47a3-a288-60a192da76ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherRealEstateOwnedMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract_29fab7e1-0f4a-4e94-abf3-0ec2d093e870" xlink:to="loc_us-gaap_OtherRealEstateOwnedMeasurementInput_212d5976-2db6-47a3-a288-60a192da76ff" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsSummarizesDifferencesBetweenFairValueandPrincipalBalanceforMortgageLoansHeldforSaleMeasureatFairValueDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsSummarizesDifferencesBetweenFairValueandPrincipalBalanceforMortgageLoansHeldforSaleMeasureatFairValueDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsSummarizesDifferencesBetweenFairValueandPrincipalBalanceforMortgageLoansHeldforSaleMeasureatFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_2711e553-8011-4d42-a0e3-81e461549542" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_9cde6999-670d-4176-a05e-700f72bea013" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_2711e553-8011-4d42-a0e3-81e461549542" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_9cde6999-670d-4176-a05e-700f72bea013" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_58996444-f108-47e4-a996-576471f7182c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_9cde6999-670d-4176-a05e-700f72bea013" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_58996444-f108-47e4-a996-576471f7182c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_58996444-f108-47e4-a996-576471f7182c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_58996444-f108-47e4-a996-576471f7182c" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_58996444-f108-47e4-a996-576471f7182c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_16fc6b18-c32e-450c-8a50-658227440872" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_58996444-f108-47e4-a996-576471f7182c" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_16fc6b18-c32e-450c-8a50-658227440872" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_888045e8-762c-43c3-8985-f73b6d1bb8fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_16fc6b18-c32e-450c-8a50-658227440872" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_888045e8-762c-43c3-8985-f73b6d1bb8fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_5e4c1984-3d0c-4da5-af0d-d5f333a658fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_888045e8-762c-43c3-8985-f73b6d1bb8fe" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_5e4c1984-3d0c-4da5-af0d-d5f333a658fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_c93d5bee-81c0-4c25-a147-69435462f21e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_888045e8-762c-43c3-8985-f73b6d1bb8fe" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_c93d5bee-81c0-4c25-a147-69435462f21e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeDuringPeriodFairValueDisclosureMember_529bb53a-d8eb-45c8-89e1-f3ec6a1e587d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeDuringPeriodFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_888045e8-762c-43c3-8985-f73b6d1bb8fe" xlink:to="loc_us-gaap_ChangeDuringPeriodFairValueDisclosureMember_529bb53a-d8eb-45c8-89e1-f3ec6a1e587d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_67445ee9-43da-4099-bb0b-b5a6d2cfa73e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_2711e553-8011-4d42-a0e3-81e461549542" xlink:to="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_67445ee9-43da-4099-bb0b-b5a6d2cfa73e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgagesHeldForSaleFairValueDisclosure_88f2df09-ba17-49a3-8bbc-070605de91f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MortgagesHeldForSaleFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_67445ee9-43da-4099-bb0b-b5a6d2cfa73e" xlink:to="loc_us-gaap_MortgagesHeldForSaleFairValueDisclosure_88f2df09-ba17-49a3-8bbc-070605de91f0" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/FairValueMeasurementsAssetsandLiabilitiesNotMeasuredandReportedatFairValueonaRecurringBasisorNonrecurringBasisDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#FairValueMeasurementsAssetsandLiabilitiesNotMeasuredandReportedatFairValueonaRecurringBasisorNonrecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/FairValueMeasurementsAssetsandLiabilitiesNotMeasuredandReportedatFairValueonaRecurringBasisorNonrecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_471497fc-16d3-44c8-be23-9a49127f4d63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3dfeac59-bef3-44af-981d-4caeaff6fdca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_471497fc-16d3-44c8-be23-9a49127f4d63" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3dfeac59-bef3-44af-981d-4caeaff6fdca" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_8e0d7df0-c869-4e42-91f6-6426f6ab647c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3dfeac59-bef3-44af-981d-4caeaff6fdca" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_8e0d7df0-c869-4e42-91f6-6426f6ab647c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_8e0d7df0-c869-4e42-91f6-6426f6ab647c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_8e0d7df0-c869-4e42-91f6-6426f6ab647c" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_8e0d7df0-c869-4e42-91f6-6426f6ab647c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c80c4e0b-ccb6-4a1a-ac4a-3f42fdae12a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_8e0d7df0-c869-4e42-91f6-6426f6ab647c" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c80c4e0b-ccb6-4a1a-ac4a-3f42fdae12a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_40fb5495-9943-4fc2-b0d3-35d2552d6738" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c80c4e0b-ccb6-4a1a-ac4a-3f42fdae12a9" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_40fb5495-9943-4fc2-b0d3-35d2552d6738" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_e03d64ec-3391-40e9-a2e2-6328d6cd23af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_40fb5495-9943-4fc2-b0d3-35d2552d6738" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_e03d64ec-3391-40e9-a2e2-6328d6cd23af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_cfee8d5e-2b26-4458-ba06-99269539b733" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_40fb5495-9943-4fc2-b0d3-35d2552d6738" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_cfee8d5e-2b26-4458-ba06-99269539b733" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_d4269e9a-3af5-43d9-a8bf-26c980bb82f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_3dfeac59-bef3-44af-981d-4caeaff6fdca" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_d4269e9a-3af5-43d9-a8bf-26c980bb82f8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d4269e9a-3af5-43d9-a8bf-26c980bb82f8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_d4269e9a-3af5-43d9-a8bf-26c980bb82f8" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_d4269e9a-3af5-43d9-a8bf-26c980bb82f8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3eec4576-ea1f-4203-a755-17206cc00d1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_d4269e9a-3af5-43d9-a8bf-26c980bb82f8" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3eec4576-ea1f-4203-a755-17206cc00d1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_1ae1b629-6a7d-4371-aea9-c3fab68b3774" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3eec4576-ea1f-4203-a755-17206cc00d1c" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_1ae1b629-6a7d-4371-aea9-c3fab68b3774" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_2c789f20-b281-44c8-b70d-c940a78c5e17" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3eec4576-ea1f-4203-a755-17206cc00d1c" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_2c789f20-b281-44c8-b70d-c940a78c5e17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_3fda6e26-910d-4c88-a7d0-9feedf4e87dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3eec4576-ea1f-4203-a755-17206cc00d1c" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_3fda6e26-910d-4c88-a7d0-9feedf4e87dc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FairValueBalanceSheetGroupingFinancialStatementCaptionsAbstract_f02a48fb-d5c9-4a69-a8f7-8c8a869e5d61" xlink:href="rnst-20250930.xsd#rnst_FairValueBalanceSheetGroupingFinancialStatementCaptionsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_471497fc-16d3-44c8-be23-9a49127f4d63" xlink:to="loc_rnst_FairValueBalanceSheetGroupingFinancialStatementCaptionsAbstract_f02a48fb-d5c9-4a69-a8f7-8c8a869e5d61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_FairValueBalanceSheetGroupingFinancialStatementCaptionsAbstract_f02a48fb-d5c9-4a69-a8f7-8c8a869e5d61" xlink:to="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_8baab0cd-fe4e-485a-a572-82595fa23afd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_8baab0cd-fe4e-485a-a572-82595fa23afd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_1eaead18-e792-4466-8e63-69fba35cc5d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_1eaead18-e792-4466-8e63-69fba35cc5d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_1abbb0b5-0eda-4fe7-b80f-b83e51bd9fd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_1abbb0b5-0eda-4fe7-b80f-b83e51bd9fd9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup_ad125a64-f1ff-41cc-82de-20d6b3680116" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup_ad125a64-f1ff-41cc-82de-20d6b3680116" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_ea8c3ab3-117f-4c1c-a828-1a0bda6525e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_NotesReceivableNet_ea8c3ab3-117f-4c1c-a828-1a0bda6525e6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetAtAmortizedValue_c050e338-4aa2-4a83-8069-d4061403a1b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ServicingAssetAtAmortizedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_ServicingAssetAtAmortizedValue_c050e338-4aa2-4a83-8069-d4061403a1b8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_fb68dde4-e09d-4e27-bf01-f9c89514f668" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract_1dc21555-320b-4d4f-932a-b03a74041fbf" xlink:to="loc_us-gaap_DerivativeAssets_fb68dde4-e09d-4e27-bf01-f9c89514f668" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_FairValueBalanceSheetGroupingFinancialStatementCaptionsAbstract_f02a48fb-d5c9-4a69-a8f7-8c8a869e5d61" xlink:to="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsFairValueDisclosure_a7edfffb-c09d-46eb-bad5-790a5d38a287" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:to="loc_us-gaap_DepositsFairValueDisclosure_a7edfffb-c09d-46eb-bad5-790a5d38a287" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShorttermDebtFairValue_7af5b530-facf-4b5b-b14c-d4c2ecbff463" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShorttermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:to="loc_us-gaap_ShorttermDebtFairValue_7af5b530-facf-4b5b-b14c-d4c2ecbff463" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_JuniorSubordinatedDebtObligationsFairValueDisclosure_0e3acc87-2ab6-4cd5-afb0-0f9053e2b276" xlink:href="rnst-20250930.xsd#rnst_JuniorSubordinatedDebtObligationsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:to="loc_rnst_JuniorSubordinatedDebtObligationsFairValueDisclosure_0e3acc87-2ab6-4cd5-afb0-0f9053e2b276" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations_91651dbc-6896-4b6b-ab3f-bc9e7765bbc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations_91651dbc-6896-4b6b-ab3f-bc9e7765bbc8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_5720bb4b-163c-4424-bbd3-b4f9b31e8066" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract_9ad06ea2-2120-4ee0-b159-eb3a0c6f3be4" xlink:to="loc_us-gaap_DerivativeLiabilities_5720bb4b-163c-4424-bbd3-b4f9b31e8066" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/OtherComprehensiveIncomeChangesintheComponentsofOtherComprehensiveIncomeLossNetofTaxDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#OtherComprehensiveIncomeChangesintheComponentsofOtherComprehensiveIncomeLossNetofTaxDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/OtherComprehensiveIncomeChangesintheComponentsofOtherComprehensiveIncomeLossNetofTaxDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_f51b8615-0ac0-4d7c-a221-b1157b0ea850" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_f51b8615-0ac0-4d7c-a221-b1157b0ea850" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_e45a3b4a-4081-4534-acbc-72fb2dc6bbd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_f51b8615-0ac0-4d7c-a221-b1157b0ea850" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_e45a3b4a-4081-4534-acbc-72fb2dc6bbd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e45a3b4a-4081-4534-acbc-72fb2dc6bbd5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e45a3b4a-4081-4534-acbc-72fb2dc6bbd5" xlink:to="loc_us-gaap_EquityComponentDomain_e45a3b4a-4081-4534-acbc-72fb2dc6bbd5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_110c639b-cd3c-47d5-9bfd-853fea5e82f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e45a3b4a-4081-4534-acbc-72fb2dc6bbd5" xlink:to="loc_us-gaap_EquityComponentDomain_110c639b-cd3c-47d5-9bfd-853fea5e82f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_e72b4585-37f7-47f8-845a-7314bfcbe9d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_110c639b-cd3c-47d5-9bfd-853fea5e82f8" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_e72b4585-37f7-47f8-845a-7314bfcbe9d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_b2601df1-7479-4abb-bd71-f8ee882e307b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_110c639b-cd3c-47d5-9bfd-853fea5e82f8" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_b2601df1-7479-4abb-bd71-f8ee882e307b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_3b44c569-e5db-4ada-a023-ee7a7f258c81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_110c639b-cd3c-47d5-9bfd-853fea5e82f8" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_3b44c569-e5db-4ada-a023-ee7a7f258c81" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_19ec0bbc-ecf0-4646-a058-1cd7924c13b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent_19ec0bbc-ecf0-4646-a058-1cd7924c13b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_82169b78-18d3-4ad2-8a9d-fe1dcd884e02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_82169b78-18d3-4ad2-8a9d-fe1dcd884e02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_8d94bdbe-657b-4f14-98bb-e6b2513d8e4d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_8d94bdbe-657b-4f14-98bb-e6b2513d8e4d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_83a7be47-17bb-48e6-aec3-8daa7685d57c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent_83a7be47-17bb-48e6-aec3-8daa7685d57c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_4be89cb5-ad09-4bfb-880c-7c01309ace00" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAociCurrentPeriodTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodTax_4be89cb5-ad09-4bfb-880c-7c01309ace00" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_93f57bb2-8405-4e7e-9c2a-0d7ea80b65b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_93f57bb2-8405-4e7e-9c2a-0d7ea80b65b5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_5f418743-a732-4249-9df3-2abb720ae939" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_5f418743-a732-4249-9df3-2abb720ae939" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_19e23f02-2dd7-40b9-8f96-b2aef734a176" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_19e23f02-2dd7-40b9-8f96-b2aef734a176" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_19ea2365-c163-43b2-b052-3384a413cd2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_3edb378b-b219-4994-838c-fe5754efaf54" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_19ea2365-c163-43b2-b052-3384a413cd2d" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/OtherComprehensiveIncomeAccumulatedBalancesforEachComponentofOtherComprehensiveIncomeLossNetofTaxDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#OtherComprehensiveIncomeAccumulatedBalancesforEachComponentofOtherComprehensiveIncomeLossNetofTaxDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/OtherComprehensiveIncomeAccumulatedBalancesforEachComponentofOtherComprehensiveIncomeLossNetofTaxDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b0dbe677-166a-40da-ad3d-1835d8038ee9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_2583ce93-e4ab-446f-aac3-1dc00310f91f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b0dbe677-166a-40da-ad3d-1835d8038ee9" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_2583ce93-e4ab-446f-aac3-1dc00310f91f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_bd8be48c-d487-4d12-bfe5-060176870a2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_2583ce93-e4ab-446f-aac3-1dc00310f91f" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_bd8be48c-d487-4d12-bfe5-060176870a2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_bd8be48c-d487-4d12-bfe5-060176870a2d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_bd8be48c-d487-4d12-bfe5-060176870a2d" xlink:to="loc_us-gaap_EquityComponentDomain_bd8be48c-d487-4d12-bfe5-060176870a2d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_29dbacfd-c115-43ed-95ec-e58038f2e79b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_bd8be48c-d487-4d12-bfe5-060176870a2d" xlink:to="loc_us-gaap_EquityComponentDomain_29dbacfd-c115-43ed-95ec-e58038f2e79b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8b679009-3f3a-4dde-a10f-3c07c11a234d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_29dbacfd-c115-43ed-95ec-e58038f2e79b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8b679009-3f3a-4dde-a10f-3c07c11a234d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_467bc550-745a-4cae-a3bc-a94da9dc8416" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8b679009-3f3a-4dde-a10f-3c07c11a234d" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_467bc550-745a-4cae-a3bc-a94da9dc8416" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_1ac990ec-a10a-470d-91eb-cf21446a4fbb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8b679009-3f3a-4dde-a10f-3c07c11a234d" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_1ac990ec-a10a-470d-91eb-cf21446a4fbb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_c80d7228-3f09-4f26-b146-a0640250d8fb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8b679009-3f3a-4dde-a10f-3c07c11a234d" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_c80d7228-3f09-4f26-b146-a0640250d8fb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_2b28331e-0fc0-4d3e-906d-e2aff1063e67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_b0dbe677-166a-40da-ad3d-1835d8038ee9" xlink:to="loc_us-gaap_StockholdersEquity_2b28331e-0fc0-4d3e-906d-e2aff1063e67" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/NetIncomePerCommonShareAntidilutiveSecuritiesDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#NetIncomePerCommonShareAntidilutiveSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/NetIncomePerCommonShareAntidilutiveSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_fbfd2415-a12f-415d-966f-99ba926a58b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_d689a3c4-4bdf-40be-b2a8-56b867eb9a21" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_fbfd2415-a12f-415d-966f-99ba926a58b0" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_d689a3c4-4bdf-40be-b2a8-56b867eb9a21" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_a9508dd3-025f-4528-ad06-eab3b4fcc41b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_d689a3c4-4bdf-40be-b2a8-56b867eb9a21" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_a9508dd3-025f-4528-ad06-eab3b4fcc41b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_a9508dd3-025f-4528-ad06-eab3b4fcc41b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_a9508dd3-025f-4528-ad06-eab3b4fcc41b" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_a9508dd3-025f-4528-ad06-eab3b4fcc41b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_44457690-fa91-485d-8607-d124290186ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_a9508dd3-025f-4528-ad06-eab3b4fcc41b" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_44457690-fa91-485d-8607-d124290186ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_c29bcabe-cce3-451d-9fe6-27fa1ada15c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_44457690-fa91-485d-8607-d124290186ad" xlink:to="loc_us-gaap_EmployeeStockOptionMember_c29bcabe-cce3-451d-9fe6-27fa1ada15c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract_c9f932ec-ba66-407d-a09c-b487f2655a19" xlink:href="rnst-20250930.xsd#rnst_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_fbfd2415-a12f-415d-966f-99ba926a58b0" xlink:to="loc_rnst_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract_c9f932ec-ba66-407d-a09c-b487f2655a19" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_a5a19410-fc99-48eb-b79f-0c51e1ef2621" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_rnst_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract_c9f932ec-ba66-407d-a09c-b487f2655a19" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_a5a19410-fc99-48eb-b79f-0c51e1ef2621" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/RegulatoryMattersCapitalandRiskBasedCapitalandLeverageRatiosDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#RegulatoryMattersCapitalandRiskBasedCapitalandLeverageRatiosDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/RegulatoryMattersCapitalandRiskBasedCapitalandLeverageRatiosDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_2f11c350-0cbc-4807-9511-34680267b55c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_2f11c350-0cbc-4807-9511-34680267b55c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_1a8b63a1-c70c-42a8-87de-6dce4cfea2b7" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable_2f11c350-0cbc-4807-9511-34680267b55c" xlink:to="loc_srt_ConsolidatedEntitiesAxis_1a8b63a1-c70c-42a8-87de-6dce4cfea2b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_1a8b63a1-c70c-42a8-87de-6dce4cfea2b7_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_1a8b63a1-c70c-42a8-87de-6dce4cfea2b7" xlink:to="loc_srt_ConsolidatedEntitiesDomain_1a8b63a1-c70c-42a8-87de-6dce4cfea2b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_3abbdef2-924e-43e0-bb09-73d8a0b5ebb1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_1a8b63a1-c70c-42a8-87de-6dce4cfea2b7" xlink:to="loc_srt_ConsolidatedEntitiesDomain_3abbdef2-924e-43e0-bb09-73d8a0b5ebb1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_e8ae80d6-c89b-43d4-9d93-bb707167537e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_3abbdef2-924e-43e0-bb09-73d8a0b5ebb1" xlink:to="loc_srt_ParentCompanyMember_e8ae80d6-c89b-43d4-9d93-bb707167537e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_4b7d7e3f-1e20-49e2-8c1b-72d63cd74d5c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_3abbdef2-924e-43e0-bb09-73d8a0b5ebb1" xlink:to="loc_srt_SubsidiariesMember_4b7d7e3f-1e20-49e2-8c1b-72d63cd74d5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapital_ce6dbeda-e869-46c0-8c44-862297ee2235" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TierOneLeverageCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_TierOneLeverageCapital_ce6dbeda-e869-46c0-8c44-862297ee2235" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneLeverageCapitalToAverageAssets_92212b27-9ac5-4df5-bc10-72ec80471eb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TierOneLeverageCapitalToAverageAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_TierOneLeverageCapitalToAverageAssets_92212b27-9ac5-4df5-bc10-72ec80471eb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommonEquityTierOneRiskBasedCapital_6a32447d-8ba1-4a01-bc57-3bf34514aa1a" xlink:href="rnst-20250930.xsd#rnst_CommonEquityTierOneRiskBasedCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_rnst_CommonEquityTierOneRiskBasedCapital_6a32447d-8ba1-4a01-bc57-3bf34514aa1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommonEquityTierOneRiskBasedCapitaltoRiskWeightedAssets_42f02064-ddcd-409e-a28a-bd5b05586757" xlink:href="rnst-20250930.xsd#rnst_CommonEquityTierOneRiskBasedCapitaltoRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_rnst_CommonEquityTierOneRiskBasedCapitaltoRiskWeightedAssets_42f02064-ddcd-409e-a28a-bd5b05586757" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapital_2da2f224-1ded-480f-a0b5-6b4548185b20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TierOneRiskBasedCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_TierOneRiskBasedCapital_2da2f224-1ded-480f-a0b5-6b4548185b20" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets_d8cc9041-676d-4c57-98ed-edc3fed750ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets_d8cc9041-676d-4c57-98ed-edc3fed750ed" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Capital_b2826ff6-887b-4ac3-83ca-9977000e5bf3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Capital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_Capital_b2826ff6-887b-4ac3-83ca-9977000e5bf3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalToRiskWeightedAssets_b83b6ea6-3494-4396-b99c-d029549901d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalToRiskWeightedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems_bf57ca9e-ed50-4758-8207-7bce43a9f365" xlink:to="loc_us-gaap_CapitalToRiskWeightedAssets_b83b6ea6-3494-4396-b99c-d029549901d8" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SegmentReportingFinancialInformationforOperatingSegmentsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SegmentReportingFinancialInformationforOperatingSegmentsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SegmentReportingFinancialInformationforOperatingSegmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_24fde6dc-5a49-4136-b9b5-16a8190328c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_b313d2ea-f04d-4e37-b2a2-aba6d68eaf55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_24fde6dc-5a49-4136-b9b5-16a8190328c2" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_b313d2ea-f04d-4e37-b2a2-aba6d68eaf55" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_b9d323f8-31e1-4ca3-99b2-1cbb3a9e648d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_b313d2ea-f04d-4e37-b2a2-aba6d68eaf55" xlink:to="loc_srt_ConsolidationItemsAxis_b9d323f8-31e1-4ca3-99b2-1cbb3a9e648d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_b9d323f8-31e1-4ca3-99b2-1cbb3a9e648d_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_b9d323f8-31e1-4ca3-99b2-1cbb3a9e648d" xlink:to="loc_srt_ConsolidationItemsDomain_b9d323f8-31e1-4ca3-99b2-1cbb3a9e648d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_fbd22d4b-b9d6-418d-93b4-645f40ebfbbc" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_b9d323f8-31e1-4ca3-99b2-1cbb3a9e648d" xlink:to="loc_srt_ConsolidationItemsDomain_fbd22d4b-b9d6-418d-93b4-645f40ebfbbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_a8ffe78b-5c9e-45a2-820f-8deee20f6331" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_fbd22d4b-b9d6-418d-93b4-645f40ebfbbc" xlink:to="loc_us-gaap_OperatingSegmentsMember_a8ffe78b-5c9e-45a2-820f-8deee20f6331" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_7e8ec5ed-3b63-4245-bdd1-485942354020" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_fbd22d4b-b9d6-418d-93b4-645f40ebfbbc" xlink:to="loc_us-gaap_CorporateNonSegmentMember_7e8ec5ed-3b63-4245-bdd1-485942354020" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_7108c238-a5b7-423d-8614-f1c60291f222" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_b313d2ea-f04d-4e37-b2a2-aba6d68eaf55" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_7108c238-a5b7-423d-8614-f1c60291f222" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_7108c238-a5b7-423d-8614-f1c60291f222_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7108c238-a5b7-423d-8614-f1c60291f222" xlink:to="loc_us-gaap_SegmentDomain_7108c238-a5b7-423d-8614-f1c60291f222_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_a9adcc73-00cd-4950-86ae-994f499b2a14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7108c238-a5b7-423d-8614-f1c60291f222" xlink:to="loc_us-gaap_SegmentDomain_a9adcc73-00cd-4950-86ae-994f499b2a14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_CommunityBanksMember_4734cb12-f6ac-4a0c-9f63-d3fa80c5ff7e" xlink:href="rnst-20250930.xsd#rnst_CommunityBanksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_a9adcc73-00cd-4950-86ae-994f499b2a14" xlink:to="loc_rnst_CommunityBanksMember_4734cb12-f6ac-4a0c-9f63-d3fa80c5ff7e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_InsuranceMember_414e9d0c-869b-40d7-92d8-8db4fed5fe26" xlink:href="rnst-20250930.xsd#rnst_InsuranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_a9adcc73-00cd-4950-86ae-994f499b2a14" xlink:to="loc_rnst_InsuranceMember_414e9d0c-869b-40d7-92d8-8db4fed5fe26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_WealthManagementMember_764babe4-a572-4262-968f-a0244c125d52" xlink:href="rnst-20250930.xsd#rnst_WealthManagementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_a9adcc73-00cd-4950-86ae-994f499b2a14" xlink:to="loc_rnst_WealthManagementMember_764babe4-a572-4262-968f-a0244c125d52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_24fde6dc-5a49-4136-b9b5-16a8190328c2" xlink:to="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_fc709d03-fabe-4eba-8736-47ed09125b11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_fc709d03-fabe-4eba-8736-47ed09125b11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_1fe7d333-a415-413a-83c0-4162f5c088c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_InterestExpenseOperating_1fe7d333-a415-413a-83c0-4162f5c088c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_39ab16be-850d-4a1d-b415-99ada62c36b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_39ab16be-850d-4a1d-b415-99ada62c36b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_49768012-325e-433c-8dac-c4bfd10b987d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_49768012-325e-433c-8dac-c4bfd10b987d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_2495c8e3-bdf9-4ac9-a98d-a8415efc3efd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_NoninterestIncome_2495c8e3-bdf9-4ac9-a98d-a8415efc3efd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_ddb1de02-9da5-4968-89ef-32a78b207b4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_LaborAndRelatedExpense_ddb1de02-9da5-4968-89ef-32a78b207b4a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_134cf8c0-494a-4fff-aa7c-201f64af718b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OccupancyNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_OccupancyNet_134cf8c0-494a-4fff-aa7c-201f64af718b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_62736b3b-70e4-4d0e-92f9-ccf49f2abf08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_62736b3b-70e4-4d0e-92f9-ccf49f2abf08" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_c79992d1-e6bc-4ee2-8ba1-fb02c7e98613" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_c79992d1-e6bc-4ee2-8ba1-fb02c7e98613" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_7774f0b5-e77e-40e3-a5da-5ed8d94e5354" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_7774f0b5-e77e-40e3-a5da-5ed8d94e5354" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_1ecd0628-04b6-4fd2-91be-301ea8be53b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_NetIncomeLoss_1ecd0628-04b6-4fd2-91be-301ea8be53b5" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_e5cff0e8-c697-4a43-b1bf-8310bb1cb036" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_Assets_e5cff0e8-c697-4a43-b1bf-8310bb1cb036" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_0767bcf5-fee7-44d8-97af-f048af6a6520" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_Liabilities_0767bcf5-fee7-44d8-97af-f048af6a6520" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_440998a4-0619-4372-97d8-6a5de4bdc104" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract_b4c24f06-cb0c-483f-b268-72c1c7c89c5f" xlink:to="loc_us-gaap_Goodwill_440998a4-0619-4372-97d8-6a5de4bdc104" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.renasantbank.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="rnst-20250930.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.renasantbank.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_079eba09-9718-4bc1-857b-df6ce966ea1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_a3376d47-86b6-48bb-93bc-c1d654e11520" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_079eba09-9718-4bc1-857b-df6ce966ea1e" xlink:to="loc_us-gaap_SubsequentEventTable_a3376d47-86b6-48bb-93bc-c1d654e11520" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_7fead213-710f-42bf-adb9-f06822c02d08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_a3376d47-86b6-48bb-93bc-c1d654e11520" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_7fead213-710f-42bf-adb9-f06822c02d08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_7fead213-710f-42bf-adb9-f06822c02d08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_7fead213-710f-42bf-adb9-f06822c02d08" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_7fead213-710f-42bf-adb9-f06822c02d08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_cdcc7202-3db8-4275-94b0-06ef09f46d85" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_7fead213-710f-42bf-adb9-f06822c02d08" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_cdcc7202-3db8-4275-94b0-06ef09f46d85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_afbe5d84-e1a3-454d-ab3d-5e0fb8b16e14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_cdcc7202-3db8-4275-94b0-06ef09f46d85" xlink:to="loc_us-gaap_SubsequentEventMember_afbe5d84-e1a3-454d-ab3d-5e0fb8b16e14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_faad1a91-77b7-4252-89be-65d030ca5dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_a3376d47-86b6-48bb-93bc-c1d654e11520" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_faad1a91-77b7-4252-89be-65d030ca5dd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_faad1a91-77b7-4252-89be-65d030ca5dd3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_faad1a91-77b7-4252-89be-65d030ca5dd3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_faad1a91-77b7-4252-89be-65d030ca5dd3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_629622e3-7983-4c8c-ac90-7b654966271a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_faad1a91-77b7-4252-89be-65d030ca5dd3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_629622e3-7983-4c8c-ac90-7b654966271a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebtMember_c5ef6ffc-d18e-46f8-bae2-89e89dcaf316" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_629622e3-7983-4c8c-ac90-7b654966271a" xlink:to="loc_us-gaap_SubordinatedDebtMember_c5ef6ffc-d18e-46f8-bae2-89e89dcaf316" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRedeemedOrCalledDuringPeriodValue_b57200ce-fa0f-4561-81d0-3cc4f29d3a41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRedeemedOrCalledDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_079eba09-9718-4bc1-857b-df6ce966ea1e" xlink:to="loc_us-gaap_StockRedeemedOrCalledDuringPeriodValue_b57200ce-fa0f-4561-81d0-3cc4f29d3a41" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases" xlink:type="arc" order="691"/>
    <link:loc xlink:type="locator" xlink:label="loc_rnst_FeesandCommissionsMortgageBanking1_26dabd55-115a-4c78-9637-d680ed9c4278" xlink:href="rnst-20250930.xsd#rnst_FeesandCommissionsMortgageBanking1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="loc_rnst_FeesandCommissionsMortgageBanking1_26dabd55-115a-4c78-9637-d680ed9c4278" xlink:type="arc" order="692"/>
  </link:definitionLink>
</link:linkbase>
