<SEC-DOCUMENT>0001179110-13-018088.txt : 20131217
<SEC-HEADER>0001179110-13-018088.hdr.sgml : 20131217
<ACCEPTANCE-DATETIME>20131217151126
ACCESSION NUMBER:		0001179110-13-018088
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20131121
FILED AS OF DATE:		20131217
DATE AS OF CHANGE:		20131217

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CORPORATE OFFICE PROPERTIES TRUST
		CENTRAL INDEX KEY:			0000860546
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				232947217
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6711 COLUMBIA GATEWAY DRIVE
		STREET 2:		SUITE 300
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046
		BUSINESS PHONE:		4432855400

	MAIL ADDRESS:	
		STREET 1:		6711 COLUMBIA GATEWAY DRIVE
		STREET 2:		SUITE 300
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CORPORATE OFFICE PROPERTIES TRUST INC
		DATE OF NAME CHANGE:	19980105

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ROYALE INVESTMENTS INC
		DATE OF NAME CHANGE:	19930328

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ROYALE REIT INC
		DATE OF NAME CHANGE:	19600201

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PICKETT C TAYLOR
		CENTRAL INDEX KEY:			0001143567

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14023
		FILM NUMBER:		131281682

	MAIL ADDRESS:	
		STREET 1:		C/O OMEGA HEALTHCARE INVESTORS
		STREET 2:		900 VICTORS WAY #350
		CITY:			ANN ARBOR
		STATE:			MI
		ZIP:			48108
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2013-11-21</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000860546</issuerCik>
        <issuerName>CORPORATE OFFICE PROPERTIES TRUST</issuerName>
        <issuerTradingSymbol>OFC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001143567</rptOwnerCik>
            <rptOwnerName>PICKETT C TAYLOR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6711 COLUMBIA GATEWAY DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>COLUMBIA</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21093</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Owned by Family Trust</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote>
    </footnotes>

    <remarks>The Reporting Person joined the Board on November 21, 2013.  On that date, the Reporting Person filed an Initial Statement of Beneficial Ownership of Securities on Form 3 to report his ownership as of that date, but the Form 3 was inadvertently filed using the Central Index Key (CIK) number of the Reporting Person's employer rather than his own CIK number.</remarks>

    <ownerSignature>
        <signatureName>Karen M. Singer, by Power of Attorney</signatureName>
        <signatureDate>2013-12-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
