<?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>0001729765</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0001145255</issuerCik>
      <issuerName>HENNESSY ADVISORS INC</issuerName>
      <secFileNumber>001-36423</secFileNumber>
      <issuerAddress>
        <com:street1>7250 REDWOOD BLVD.</com:street1>
        <com:street2>SUITE 200</com:street2>
        <com:city>NOVATO</com:city>
        <com:stateOrCountry>CA</com:stateOrCountry>
        <com:zipCode>94945</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>415-899-1555</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Fahy Kathryn</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Charles Schwab Corp.</name>
        <address>
          <com:street1>3000 Schwab Way</com:street1>
          <com:city>Westlake</com:city>
          <com:stateOrCountry>TX</com:stateOrCountry>
          <com:zipCode>76262</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>10000</noOfUnitsSold>
      <aggregateMarketValue>101600.00</aggregateMarketValue>
      <noOfUnitsOutstanding>7902394</noOfUnitsOutstanding>
      <approxSaleDate>05/11/2026</approxSaleDate>
      <securitiesExchangeName>Nasdaq</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>09/12/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Vested RSAs</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>1158</amountOfSecuritiesAcquired>
      <paymentDate>09/12/2021</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>09/18/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Vested RSAs</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2323</amountOfSecuritiesAcquired>
      <paymentDate>09/18/2021</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>09/06/2022</acquiredDate>
      <natureOfAcquisitionTransaction>Vested RSAs</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>1498</amountOfSecuritiesAcquired>
      <paymentDate>09/06/2022</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>09/22/2025</acquiredDate>
      <natureOfAcquisitionTransaction>Vested RSAs</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>5225</amountOfSecuritiesAcquired>
      <paymentDate>09/22/2025</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>05/11/2026</noticeDate>
      <signature>Kathryn Fahy</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
