EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report dated February 20, 1995 included in this Form 10-K into the previously filed Registration Statement File Nos. 33-51493, 2-98222, 33-29375 and 33-37380 on Form S-8 of Omnicom Group Inc. and into the previously filed Registration Statement File Nos. 33-29375, 33-37380, 33-52385, 33-54110, 33-62976, 33-63200, 33-62978, 33-61852, 33-50409, 33-50267, 33-50271, 33-50269, 33-50257, 33-45881, 33-54851 and 33-55235 on Form S-3 of Omnicom Group Inc. ARTHUR ANDERSEN LLP New York, New York March 28, 1995 S-12