<SEC-DOCUMENT>0001144204-15-006734.txt : 20150206
<SEC-HEADER>0001144204-15-006734.hdr.sgml : 20150206
<ACCEPTANCE-DATETIME>20150206163125
ACCESSION NUMBER:		0001144204-15-006734
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20141231
FILED AS OF DATE:		20150206
DATE AS OF CHANGE:		20150206

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MDC PARTNERS INC
		CENTRAL INDEX KEY:			0000876883
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ADVERTISING AGENCIES [7311]
		IRS NUMBER:				980364441
		STATE OF INCORPORATION:			A6
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		745 FIFTH AVENUE, 19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10151
		BUSINESS PHONE:		646 429 1800

	MAIL ADDRESS:	
		STREET 1:		745 FIFTH AVENUE, 19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10151

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MDC CORP INC
		DATE OF NAME CHANGE:	20001204

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MDC COMMUNICATIONS CORP
		DATE OF NAME CHANGE:	19961028

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MDC CORPORATION
		DATE OF NAME CHANGE:	19950419

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NADAL MILES
		CENTRAL INDEX KEY:			0001283589

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13718
		FILM NUMBER:		15584998

	MAIL ADDRESS:	
		STREET 1:		PO BOX N1991
		STREET 2:		PARADISE ISLAND
		CITY:			NASSAU
		STATE:			C5
		ZIP:			999999999
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>v400671_5.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2014-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000876883</issuerCik>
        <issuerName>MDC PARTNERS INC</issuerName>
        <issuerTradingSymbol>MDCA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001283589</rptOwnerCik>
            <rptOwnerName>NADAL MILES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MDC PARTNERS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>45 HAZELTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5R 2E3</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, CEO and President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Shares</value>
            </securityTitle>
            <transactionCoding></transactionCoding>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5692383</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>30340</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5662043</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These Class A Shares were donated to charitable institutions by the Reporting Person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Miles S. Nadal</signatureName>
        <signatureDate>2015-02-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
