<SEC-DOCUMENT>0001284084-17-000021.txt : 20171221
<SEC-HEADER>0001284084-17-000021.hdr.sgml : 20171221
<ACCEPTANCE-DATETIME>20171221161228
ACCESSION NUMBER:		0001284084-17-000021
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20171220
FILED AS OF DATE:		20171221
DATE AS OF CHANGE:		20171221

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CROATTI CYNTHIA
		CENTRAL INDEX KEY:			0001260756

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08504
		FILM NUMBER:		171269587

	MAIL ADDRESS:	
		STREET 1:		68 JONSPIN ROAD
		CITY:			WILMINGTON
		STATE:			DC
		ZIP:			01887

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNIFIRST CORP
		CENTRAL INDEX KEY:			0000717954
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PERSONAL SERVICES [7200]
		IRS NUMBER:				042103460
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0830

	BUSINESS ADDRESS:	
		STREET 1:		68 JONSPIN RD
		CITY:			WILMINGTON
		STATE:			MA
		ZIP:			01887
		BUSINESS PHONE:		(978) 658-8888

	MAIL ADDRESS:	
		STREET 1:		68 JONSPIN ROAD
		CITY:			WILMINGTON
		STATE:			MA
		ZIP:			01887

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERSTATE UNIFORM SERVICES CORP/MA
		DATE OF NAME CHANGE:	19840410
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_151389073309327.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-12-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000717954</issuerCik>
        <issuerName>UNIFIRST CORP</issuerName>
        <issuerTradingSymbol>UNF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001260756</rptOwnerCik>
            <rptOwnerName>CROATTI CYNTHIA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>68 JONSPIN ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WILMINGTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01887</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive VP and Treasurer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-12-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1332</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1332</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2750703</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Partnership</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>52734</value>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>68534</value>
                    <footnoteId id="F8"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock units granted under the UniFirst Corporation Amended and Restated 2010 Stock Option and Incentive Plan. Such restricted stock units vest 100% on the fifth anniversary of the grant date.</footnote>
        <footnote id="F2">Consists of 1,332 restricted stock units that vest 100% on December 20, 2022.</footnote>
        <footnote id="F3">Represents 1,734,986 shares owned directly by The Queue Limited Partnership and indirectly by each of Queue Management Associates, Inc., The Ronald D. Croatti Trust - 1993, Cynthia Croatti and Cecelia Levenstein. Queue Management Associates, Inc. is the general partner of The Queue Limited Partnership. The Ronald D. Croatti Trust - 1993, Cynthia Croatti and Cecilia Levenstein are the sole shareholders of Queue Management Associates, Inc., and Carol Croatti, Cynthia Croatti and Cecelia Levenstein are directors of Queue Management Associates, Inc. Carol Croatti is a beneficiary, but not a trustee, of a trust holding a limited partnership interest in The Queue Limited Partnership. Cynthia Croatti and Cecelia Levenstein are trustees or beneficiaries of various trusts which hold limited partnership interests in The Queue Limited Partnership.</footnote>
        <footnote id="F4">Also includes 1,015,717 shares owned directly by The Red Cat Limited Partnership and indirectly by each of Red Cat Management Associates, Inc., The Ronald D. Croatti Trust - 1993 and Cynthia Croatti. Red Cat Management Associates, Inc. is the general partner of The Red Cat Limited Partnership. The Ronald D. Croatti Trust - 1993 and Cynthia Croatti are the sole shareholders of Red Cat Management Associates, Inc. and Carol Croatti and Cynthia Croatti are directors of Red Cat Management Associates, Inc. Carol Croatti is the beneficiary, but not a trustee, of a trust holding a limited partnership interest in The Red Cat Limited Partnership. Cynthia Croatti and Cecelia Levenstein are trustees or beneficiaries of certain trusts which hold limited partnership interests in The Red Cat Limited Partnership.</footnote>
        <footnote id="F5">Each of the aforementioned reporting persons disclaims beneficial ownership of these reported securities, except to the extent of his, her or its pecuniary interest therein, and this report shall not be deemed an admission that such persons are the beneficial owners of these securities for purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F6">Represents 4,374 shares owned directly by The Marie Croatti QTIP Trust. Cynthia Croatti is trustee of The Marie Croatti QTIP Trust. Cynthia Croatti disclaims beneficial ownership of these reported securities, except to the extent of her pecuniary interest therein, and this report shall not be deemed an admission that she is the beneficial owner of these securities for purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F7">Cynthia Croatti is a trustee of The Samuel E. Brown Gallo Trust - 1989 and The Nicholas C. Brown Gallo Trust - 1989, which as of the date of filing this report, each directly owns a portion of the 48,000 reported securities. Cynthia Croatti disclaims beneficial ownership of these reported securities, except to the extent of her pecuniary interest therein, and this report shall not be deemed an admission that she is the beneficial owner of the securities for purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F8">Cynthia Croatti is the manager of Trilogy Investment Partners LLC, which as of the date of filing this report, directly owns the reported securities. Cynthia Croatti disclaims beneficial ownership of these reported securities, except to the extent of her pecuniary interest therein, and this report shall not be deemed an admission that she is the beneficial owner of the securities for purposes of Section 16 or any other purpose.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ David Whitman, Attorney-in-Fact</signatureName>
        <signatureDate>2017-12-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
