<SEC-DOCUMENT>0001209191-21-057953.txt : 20210928
<SEC-HEADER>0001209191-21-057953.hdr.sgml : 20210928
<ACCEPTANCE-DATETIME>20210928172912
ACCESSION NUMBER:		0001209191-21-057953
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210927
FILED AS OF DATE:		20210928
DATE AS OF CHANGE:		20210928

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ross William Masters
		CENTRAL INDEX KEY:			0001688445

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08504
		FILM NUMBER:		211288470

	MAIL ADDRESS:	
		STREET 1:		C/O UNIFIRST CORPORATION
		STREET 2:		68 JONSPIN ROAD
		CITY:			WILMINGTON
		STATE:			MA
		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:			0829

	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>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-09-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001688445</rptOwnerCik>
            <rptOwnerName>Ross William Masters</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNIFIRST CORP</rptOwnerStreet1>
            <rptOwnerStreet2>68 JONSPIN ROAD</rptOwnerStreet2>
            <rptOwnerCity>WILMINGTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01887</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>64</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>225.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>65</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4413</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares sold pursuant to a Rule 10b5-1 sales plan.</footnote>
        <footnote id="F2">Consists of 1,044 restricted stock units that vest 100% on December 20, 2022, 1,231 restricted stock units that vest 100% on October 22, 2023, 969 restricted stock units that vest 60% on October 29, 2022, an additional 20% on October 29, 2023 and the remaining 20% on October 29, 2024, and 1,169 restricted stock units that vest 60% on October 26, 2023, an additional 20% on October 26, 2024 and the remaining 20% on October 26, 2025.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Steven S. Sintros, Attorney-in-Fact</signatureName>
        <signatureDate>2021-09-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
