content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001311380</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001521951</issuerCik>
        <issuerName>FIRST BUSINESS FINANCIAL SERVICES, INC.</issuerName>
        <secFileNumber>001-34095</secFileNumber>
        <issuerAddress>
          <com:street1>401 CHARMANY DRIVE</com:street1>
          <com:city>MADISON</com:city>
          <com:stateOrCountry>WI</com:stateOrCountry>
          <com:zipCode>53719</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>608-238-8008</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MELOY MARK J</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>CAPIS</name>
          <address>
            <com:street1>1700 Pacific Avenue</com:street1>
            <com:street2>Suite 1100</com:street2>
            <com:city>Dallas</com:city>
            <com:stateOrCountry>TX</com:stateOrCountry>
            <com:zipCode>75201</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>5000</noOfUnitsSold>
        <aggregateMarketValue>204150.00</aggregateMarketValue>
        <noOfUnitsOutstanding>8294589</noOfUnitsOutstanding>
        <approxSaleDate>08/12/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/16/2022</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>839</amountOfSecuritiesAcquired>
        <paymentDate>02/16/2022</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>04/18/2022</acquiredDate>
        <natureOfAcquisitionTransaction>Performance Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>2658</amountOfSecuritiesAcquired>
        <paymentDate>04/18/2022</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>08/16/2022</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>198</amountOfSecuritiesAcquired>
        <paymentDate>08/16/2022</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/16/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>751</amountOfSecuritiesAcquired>
        <paymentDate>02/16/2023</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>04/17/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Performance Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>554</amountOfSecuritiesAcquired>
        <paymentDate>04/17/2023</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>08/09/2024</noticeDate>
        <planAdoptionDates>
          <planAdoptionDate>08/09/2024</planAdoptionDate>
        </planAdoptionDates>
        <signature>Mark J. Meloy</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 5031}]
text: 144
  0001311380
  XXXXXXXX
  LIVE
  0001521951
  FIRST BUSINESS FINANCIAL SERVICES, INC.
  001-34095
  401 CHARMANY DRIVE
  MADISON
  WI
  53719
  608-238-8008
  MELOY MARK J
  Officer
  Common
  CAPIS
  1700 Pacific Avenue
  Suite 1100
  Dallas
  TX
  75201
  5000
  204150.00
  8294589
  08/12/2024
  NASDAQ
  Common
  02/16/2022
  Restricted Stock Vesting
  Issuer
  N
  839
  02/16/2022
  Compensation
  Common
  04/18/2022
  Performance Restricted Stock Vesting
  Issuer
  N
  2658
  04/18/2022
  Compensation
  Common
  08/16/2022
  Restricted Stock Vesting
  Issuer
  N
  198
  08/16/2022
  Compensation
  Common
  02/16/2023
  Restricted Stock Vesting
  Issuer
  N
  751
  02/16/2023
  Compensation
  Common
  04/17/2023
  Performance Restricted Stock Vesting
  Issuer
  N
  554
  04/17/2023
  Compensation
  Y
  08/09/2024
  08/09/2024
  Mark J. Meloy