Omnicom Group Inc.

Omnicom Group is one of the legacy ‘Big Four’ marketing-services holding companies — alongside WPP, Publicis, and now the defunct standalone Interpublic Group — with a portfolio of advertising, media-buying, public-relations, healthcare-communications, and CRM agency brands including BBDO Worldwide, DDB Worldwide, TBWA Worldwide, OMD, PHD, and the Annalect data-and-analytics unit. Headquartered in New York and trading on the NYSE under OMC, the company reported $15.3 billion in 2024 revenue; $17.27 billion in FY2025 (+10.1% YoY); and $6.2 billion in Q1 2026 — the first full quarter following the November 2025 close of the Interpublic Group acquisition.

The editorial reason Omnicom sits in our coverage as a tracked entity is the all-stock combination with Interpublic Group — announced December 9, 2024, valued at approximately $13.25 billion, and closed on November 26, 2025 — which consolidated Omnicom and IPG into the largest marketing-services holding company in the world and delisted IPG from the NYSE on the same date. The post-close leadership structure installed former IPG CEO Philippe Krakowsky and longtime Omnicom executive Daryl Simm as Co-Presidents and COOs reporting to Wren. The targeted approximately $750 million in annual cost synergies — revised upward to $900 million in 2026 guidance and $1.5 billion by mid-2028 — and Stagwell CEO Mark Penn’s prediction that the synergies would translate to roughly 7,500 affected industry roles remain the most-cited public framing of the deal’s human cost.

Omnicom CEO John Wren, who has led the company since 1997, now leads the combined entity. Omnicom files standard SEC quarterly and annual reports as a NYSE-listed company under OMC, with the most recent 10-K, 10-Q, and 8-K filings maintained on the Omnicom Investor Relations site and on EDGAR.