<SEC-DOCUMENT>0001144215-22-000075.txt : 20220701
<SEC-HEADER>0001144215-22-000075.hdr.sgml : 20220701
<ACCEPTANCE-DATETIME>20220701160621
ACCESSION NUMBER:		0001144215-22-000075
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20220629
FILED AS OF DATE:		20220701
DATE AS OF CHANGE:		20220701

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			AVEDON MARCIA J
		CENTRAL INDEX KEY:			0001215124

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16583
		FILM NUMBER:		221061403

	MAIL ADDRESS:	
		STREET 1:		C/O INGERSOLL-RAND COMPANY
		STREET 2:		800-E BEATY STREET
		CITY:			DAVIDSON
		STATE:			NC
		ZIP:			28036

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ACUITY BRANDS INC
		CENTRAL INDEX KEY:			0001144215
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC LIGHTING & WIRING EQUIPMENT [3640]
		IRS NUMBER:				582632672
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		1170 PEACHTREE STREET, NE
		STREET 2:		SUITE 2300
		CITY:			ATLANTA
		STATE:			GA
		ZIP:			30309-7676
		BUSINESS PHONE:		404-853-1400

	MAIL ADDRESS:	
		STREET 1:		1170 PEACHTREE STREET, NE
		STREET 2:		SUITE 2300
		CITY:			ATLANTA
		STATE:			GA
		ZIP:			30309-7676

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	L&C SPINCO INC
		DATE OF NAME CHANGE:	20010629
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_165670596553202.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-06-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001144215</issuerCik>
        <issuerName>ACUITY BRANDS INC</issuerName>
        <issuerTradingSymbol>AYI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001215124</rptOwnerCik>
            <rptOwnerName>AVEDON MARCIA J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ACUITY BRANDS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1170 PEACHTREE STREET, NE, SUITE 2300</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30309</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Deferred Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2022-06-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>545</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>153.24</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2023-01-25</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>545.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>545</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1-for-1</footnote>
        <footnote id="F2">Deferred Restricted Stock Units (DSUs) issued pursuant to the Issuer's Amended and Restated 2012 Omnibus Stock Incentive Compensation Plan. The DSUs resulted from the Reporting Person's election to receive a portion of her prorata annual director fees in the form of a deferred stock unit award. The DSUs will vest in full on the first anniversary of the grant date, or, if earlier, the date of the next subsequent annual meeting of the Issuer's stockholders following the grant date. Once vested, shares underlying the DSUs will be payable upon retirement in either lump sum or five annual installments.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jill A. Gilmer, under Power of Attorney for Marcia J. Avedon</signatureName>
        <signatureDate>2022-07-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
