<SEC-DOCUMENT>0000891092-15-003570.txt : 20150428
<SEC-HEADER>0000891092-15-003570.hdr.sgml : 20150428
<ACCEPTANCE-DATETIME>20150428171018
ACCESSION NUMBER:		0000891092-15-003570
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150424
FILED AS OF DATE:		20150428
DATE AS OF CHANGE:		20150428

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OMNICOM GROUP INC.
		CENTRAL INDEX KEY:			0000029989
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ADVERTISING AGENCIES [7311]
		IRS NUMBER:				131514814
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		437 MADISON AVE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		2124153600

	MAIL ADDRESS:	
		STREET 1:		437 MADISON AVE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OMNICOM GROUP INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DOYLE DANE BERNBACH GROUP INC
		DATE OF NAME CHANGE:	19861117

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DOYLE DANE BERNBACH INTERNATIONAL INC
		DATE OF NAME CHANGE:	19850604

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hewitt Dennis E.
		CENTRAL INDEX KEY:			0001497687

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10551
		FILM NUMBER:		15799492

	MAIL ADDRESS:	
		STREET 1:		437 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>e63881_4.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-04-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000029989</issuerCik>
        <issuerName>OMNICOM GROUP INC.</issuerName>
        <issuerTradingSymbol>OMC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001497687</rptOwnerCik>
            <rptOwnerName>Hewitt Dennis E.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OMNICOM GROUP INC.</rptOwnerStreet1>
            <rptOwnerStreet2>437 MADISON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Treasurer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.15 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-04-24</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8112</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>37713</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.15 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-04-24</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3034</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>77.50</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34679</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On April 4, 2012, the reporting person was granted performance restricted stock units (&quot;PRSUs&quot;) which vest based on the company's return on equity as compared to that of an industry peer group. On April 24, 2015, the compensation committee of the board of directors of the company determined that the performance criteria had been met, resulting in the vesting of these shares.</footnote>
        <footnote id="F2">Represents shares withheld by the company for payment of tax liability incident to the vesting of PRSUs originally granted to the reporting person on April 8, 2011 and April 4, 2012.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Michael J. O'Brien, Attorney in Fact for Dennis E. Hewitt</signatureName>
        <signatureDate>2015-04-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
