Omnicom is a holding company for advertising, marketing and communications agencies. It sells services that include media planning and buying, creative work, public relations, health-care marketing, branding and retail marketing, events, and customer data and technology consulting. Its clients are many of the largest companies in the world. Its agencies include BBDO, TBWA, McCann, OMD, FleishmanHillard and Ketchum.
Omnicom earns its money by providing these services to clients. It groups its agencies into four global networks: Omnicom Advertising, Omnicom Media, the DAS Group of Companies and the Communications Consultancy Network. Its clients work in nearly every sector, and no one industry made up more than 15% of revenue in 2025. Its largest client was 2.4% of revenue, and its 100 largest clients were approximately 54%.
On November 26, 2025, Omnicom completed its merger with Interpublic Group (IPG), which became a wholly owned subsidiary. After the merger, former Omnicom shareholders owned approximately 60.6% of the combined company and former IPG shareholders approximately 39.4%. Omnicom says it is building generative AI into its planning, creative, media and analytics work.