Omnicom Group is an American global advertising, marketing, and corporate communications holding company. It is one of the world's largest advertising and communications services conglomerates and one of the Big Four agencies (the others are WPP, Interpublic, and Publicis Groupe). It serves over 5,000 clients from 1,500 offices in over 100 countries and regions.
Its subsidiaries include BBDO, TBWA Worldwide, DDB Worldwide, Ketchum, FleishmanHillard, and OMD.

Omnicom Group is a global leader in advertising, marketing, and corporate communications. Through its global network and its numerous specialized agencies, Omnicom provides advertising, strategic media planning and buying, direct marketing, promotions, public relations, and other specialized communications consulting services to over 5,000 clients in more than 100 countries.
Omnicom Media Group, a subsidiary of Omnicom Group, is the world's most award-winning media group, having been recognized for ten consecutive years. [5-6] It owns three agencies: OMD, PHD, and Hearts & Science. It leads over 22,000 industry experts in over 100 countries, serving clients across all sectors.
Company Name: Omnicom Group.
Official Domain Name: omnicomgroup.com.
Domain Created: April 23, 1998.
Country: United States.
Headquarters: New York, USA.
Founded: 1986.