<SEC-DOCUMENT>0001104659-18-020940-index.html : 20180328
<SEC-HEADER>0001104659-18-020940.hdr.sgml : 20180328
<ACCEPTANCE-DATETIME>20180328160621
ACCESSION NUMBER:		0001104659-18-020940
CONFORMED SUBMISSION TYPE:	DEFA14A
PUBLIC DOCUMENT COUNT:		5
FILED AS OF DATE:		20180328
DATE AS OF CHANGE:		20180328
EFFECTIVENESS DATE:		20180328

FILER:

	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

	FILING VALUES:
		FORM TYPE:		DEFA14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14023
		FILM NUMBER:		18718815

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>DEFA14A
<SEQUENCE>1
<FILENAME>a18-2912_3defa14a.htm
<DESCRIPTION>DEFA14A
<TEXT>
Document 1 - file: a18-2912_3defa14a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g29123bgi001.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g29123bgi001.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g29123bgi002.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g29123bgi002.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g29123bgi003.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g29123bgi003.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g29123bgi004.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g29123bgi004.gif

</DOCUMENT>
</SEC-DOCUMENT>