<SEC-DOCUMENT>0001140361-16-077198.txt : 20160818
<SEC-HEADER>0001140361-16-077198.hdr.sgml : 20160818
<ACCEPTANCE-DATETIME>20160818182426
ACCESSION NUMBER:		0001140361-16-077198
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160816
FILED AS OF DATE:		20160818
DATE AS OF CHANGE:		20160818

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HENNESSY ADVISORS INC
		CENTRAL INDEX KEY:			0001145255
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		IRS NUMBER:				680176227
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		7250 REDWOOD BLVD.
		STREET 2:		SUITE 200
		CITY:			NOVATO
		STATE:			CA
		ZIP:			94945
		BUSINESS PHONE:		415-899-1555

	MAIL ADDRESS:	
		STREET 1:		7250 REDWOOD BLVD.
		STREET 2:		SUITE 200
		CITY:			NOVATO
		STATE:			CA
		ZIP:			94945

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SEAVEY THOMAS L
		CENTRAL INDEX KEY:			0001165097

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36423
		FILM NUMBER:		161841719

	MAIL ADDRESS:	
		STREET 1:		7250 REDWOOD BLVD.
		STREET 2:		SUITE 200
		CITY:			NOVATO
		STATE:			CA
		ZIP:			94945
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-08-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001145255</issuerCik>
        <issuerName>HENNESSY ADVISORS INC</issuerName>
        <issuerTradingSymbol>HNNA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001165097</rptOwnerCik>
            <rptOwnerName>SEAVEY THOMAS L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7250 REDWOOD BOULEVARD, SUITE 200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NOVATO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94945</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-08-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2158</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>37.7299</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>32687</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price in Column 4 is a weighted average price. The prices actually received ranged from $37.68 to $37.76. The reporting person has provided to the issuer, and will provide to any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range for all transactions reported in this Form 4 utilizing a weighted average price.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Peter D. Fetzer, Attorney-in-Fact for Thomas L. Seavey</signatureName>
        <signatureDate>2016-08-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
