<SEC-DOCUMENT>0001140361-14-042992.txt : 20141120
<SEC-HEADER>0001140361-14-042992.hdr.sgml : 20141120
<ACCEPTANCE-DATETIME>20141120183828
ACCESSION NUMBER:		0001140361-14-042992
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20141114
FILED AS OF DATE:		20141120
DATE AS OF CHANGE:		20141120

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MACERICH CO
		CENTRAL INDEX KEY:			0000912242
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				954448705
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		401 WILSHIRE BLVD
		STREET 2:		STE 700
		CITY:			SANTA MONICA
		STATE:			CA
		ZIP:			90401
		BUSINESS PHONE:		3103946000

	MAIL ADDRESS:	
		STREET 1:		401 WILSHIRE BLVD SUITE 700
		CITY:			SANTA MONICA
		STATE:			CA
		ZIP:			90401

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			1700480 ONTARIO INC
		CENTRAL INDEX KEY:			0001625247
		STATE OF INCORPORATION:			A6
		FISCAL YEAR END:			1031

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12504
		FILM NUMBER:		141240339

	BUSINESS ADDRESS:	
		STREET 1:		20 QUEEN STREET WEST
		CITY:			TORONTO
		STATE:			A6
		ZIP:			M5H 3R4
		BUSINESS PHONE:		416-598-8200

	MAIL ADDRESS:	
		STREET 1:		20 QUEEN STREET WEST
		CITY:			TORONTO
		STATE:			A6
		ZIP:			M5H 3R4

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ONTARIO TEACHERS PENSION PLAN BOARD
		CENTRAL INDEX KEY:			0000937567
		STATE OF INCORPORATION:			A6
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12504
		FILM NUMBER:		141240340

	BUSINESS ADDRESS:	
		STREET 1:		5650 YONGE STREET
		STREET 2:		NORTH YORK
		CITY:			TORONTO
		STATE:			A6
		ZIP:			M2M 4H5
		BUSINESS PHONE:		4167305300

	MAIL ADDRESS:	
		STREET 1:		5650 YONGE STREET
		STREET 2:		NORTH YORK
		CITY:			TORONTO
		STATE:			A6
		ZIP:			M2M 4H5
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2014-11-14</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000912242</issuerCik>
        <issuerName>MACERICH CO</issuerName>
        <issuerTradingSymbol>MAC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000937567</rptOwnerCik>
            <rptOwnerName>ONTARIO TEACHERS PENSION PLAN BOARD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5650 YONGE STREET, 3RD FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M2M 4H5</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001625247</rptOwnerCik>
            <rptOwnerName>1700480 ONTARIO INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>20 QUEEN STREET WEST, 5TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5H 3R4</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17140845</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27682</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Prior to the Reporting Persons becoming subject to Section 16, Ontario Teachers' Pension Plan effected a short sale of 1,000 shares of Common Stock through a wholly-owned subsidiary of Ontario Teachers' Pension Plan that remained open until November 18, 2014 when the wholly-owned subsidiary closed out the short position.</footnote>
        <footnote id="F2">17,140,845 shares of Common Stock are owned directly by 1700480 Ontario Inc., which is a wholly owned subsidiary of Ontario Teachers' Pension Plan. Ontario Teachers' Pension Plan is an indirect beneficial owner of such reported securities.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Sandra Hardy, Authorized Person on behalf of 1700480 Ontario Inc.</signatureName>
        <signatureDate>2014-11-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Rossana Di Lieto, Chief Compliance Officer on behalf of Ontario Teachers' Pension Plan</signatureName>
        <signatureDate>2014-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
