PROSPECTUS SUPPLEMENT
(To Prospectus Dated January 28, 1998)

                               OMNICOM GROUP INC.
                         219,205 Shares of Common Stock
                                ($.15 Par Value)

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This  document  supplements  the  Prospectus  dated January 28, 1998 relating to
219,205 shares of Common Stock, par value $.15 per share (the "Common Stock") of
the Omnicom Group Inc., a New York  corporation  ("Omnicom"  or the  "Company").
Each  share of Common  Stock  offered  hereby  was issued  upon  exchange  of an
Exchangeable  Share (an "Exchangeable  Share") of Omnicom Canada Inc. ("OCI"), a
corporation  incorporated  under  the laws of  Ontario,  originally  issued in a
private  offering in Canada by Palmer Jarvis Inc. (now amalgamated into OCI) and
the Company.  The shares of Common Stock offered hereby were initially  acquired
upon exchange of the Exchangeable  Shares in a private offering in Canada.  This
Prospectus Supplement is incorporated by reference into the Prospectus,  and all
terms used herein shall have the meaning assigned to them in the Prospectus.  On
July 31, 2002 the closing  price of the Common Stock as reported on the New York
Stock Exchange was $53.31 per share. The Common Stock is traded under the symbol
"OMC."

None of the Selling Shareholders owns in excess of 1% of the Common Stock of the
Company and since the  Selling  Shareholders  may sell all,  some or none of the
shares of Common Stock offered hereby,  no estimate can be made of the aggregate
number of shares of Common Stock that will be owned by each Selling  Shareholder
upon completion of the offering to which this Prospectus  Supplement relates. In
accordance with the Section of the Prospectus  entitled  "Selling  Shareholders"
(which  appears on page 10 of the  Prospectus),  the  following  information  is
provided with respect to the beneficial owners of the Common Stock:

                                    Amount of Shares          Amount of
                                    Beneficially Owned        Shares to be
Name of Selling Shareholder(s)      as of July 31, 2002       Offered for Sale
------------------------------      -------------------       ----------------
Frank William Palmer                       791                      791

Except for the purchase of the shares of Common Stock and his position with OCI,
the Selling Shareholder has not had a material  relationship with the Company or
any of its affiliates within the past three years.

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THESE  SECURITIES  HAVE NOT BEEN APPROVED OR  DISAPPROVED  BY THE SECURITIES AND
EXCHANGE  COMMISSION OR ANY STATE SECURITY COMMISSION NOR HAS THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES  COMMISSION PASSED UPON THE ACCURACY
OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL
OFFENSE.
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           The date of this Prospectus Supplement is August 5, 2002.