Omnicom Group: Inside the World's Largest Communications Holding Company (2026 Update)

Edited on Sep 15, 2026.

Omnicom Group (NYSE: OMC) is the world’s largest marketing and communications holding company following its November 26, 2025 acquisition of Interpublic Group (IPG). Headquartered in New York and led by Chairman and CEO John Wren, the combined company serves more than 5,000 clients across 100+ countries through a portfolio of advertising, public relations, digital, healthcare, and media agencies.

The PR portfolio sits inside Omnicom Public Relations Group (OPRG), led by CEO Chris Foster. This page covers Omnicom Group as a whole, the parent public company, the IPG deal, and its full agency portfolio beyond PR. For the PR subsidiary's four cornerstone networks and its February 2026 restructuring in full detail, see the OPRG profile.

Overview

Omnicom Group was formed in 1986 through the merger of BBDO, DDB, and Needham Harper Worldwide. The company has grown through four decades of acquisitions across advertising, public relations, healthcare communications, digital, and media planning. The November 2025 IPG acquisition was the largest transaction in the holding company’s history, and the largest combination in the agency industry to date.

The IPG transaction was announced December 8, 2024 and approved by shareholders March 18, 2025. The U.S. Federal Trade Commission cleared the deal on June 23, 2025 with a consent order. Following final regulatory approvals in late 2025, the acquisition closed on November 26, 2025. Each share of IPG common stock was converted into 0.344 shares of Omnicom common stock. The combined platform has revenues of more than $25 billion and roughly 100,000 employees across 100+ countries, surpassing WPP for the global lead.

Beyond PR: advertising, media, and commerce

Public relations is one division of a much larger company. Omnicom's advertising networks operate under BBDO, DDB, and TBWA, which trace back to the 1986 founding merger and IPG's McCann heritage; FCB and DDB Worldwide are being folded into these three surviving flagship networks post-IPG. Media planning and buying runs through OMD, PHD, and Hearts & Science, combined with IPG's Mediabrands units, including UM, Initiative, Mediahub, and MAGNA. Omni is the company's audience-intelligence platform, and Flywheel Digital, acquired for $835 million in December 2023, is its digital commerce and retail-media arm focused on Amazon, Walmart, and other marketplaces. Together, advertising, media, and commerce make up most of Omnicom's roughly $25 billion in pro-forma revenue, with PR as a meaningful but smaller division inside OPRG.

The Interpublic Acquisition (November 2025)

The IPG portfolio brought several major PR brands into Omnicom’s PR holding, including Weber Shandwick, Golin, R&CPMK, DeVries Global, Current Global, Carmichael Lynch Relate, and Jack Health. For the standalone history of that roster before the merger, see Inside IPG: The Holding Company's PR Roster. The combination immediately raised the question of how these brands would coexist with Omnicom’s legacy PR portfolio: FleishmanHillard, Ketchum, Porter Novelli, MMC, Rabin Martin, Cone Communications, and the public affairs network.

Chris Foster was named CEO of the combined PR holding, Omnicom Public Relations Group (OPRG). OPRG itself dates back to a February 2016 integration of ten Omnicom PR firms under Karen Van Bergen; Foster's first major decision as its post-merger CEO was a restructuring of the overlapping legacy and IPG PR brands, announced February 10, 2026: Golin and Ketchum merged into Golin Ketchum, Porter Novelli was absorbed into FleishmanHillard, R&CPMK was dissolved, and Weber Shandwick, MMC, and the public affairs network were left unchanged. Full detail on OPRG's history, the restructuring, the four cornerstone networks, and the public affairs and specialty brands is at the OPRG profile. See also Omnicom Swallowed IPG for the full deal analysis.

Publicis Groupe: the other side of the holding-company map

Omnicom does not stand alone at the top. Publicis Groupe, Paris-headquartered and the world's third-largest communications group, runs the other major global network. Its PR arm is MSL (formerly MSLGROUP), operating alongside Saatchi & Saatchi, Leo Burnett, Zenith, and Publicis Worldwide, led by Arthur Sadoun.

The proposed 2013 Publicis-Omnicom merger would have collapsed both groups into a single $35-billion-plus holding company. The deal was abandoned in 2014. A decade later, Omnicom answered it with the IPG acquisition instead.

Leadership and compensation

• John Wren, Chairman and CEO, Omnicom Group. 2025 total compensation: $69,865,846. Base salary reset to $1 through December 2028.
• Chris Foster, CEO, Omnicom Public Relations Group
• JJ Carter, Global CEO, FleishmanHillard
• Matt Neale, CEO, Golin Ketchum
• Tamara Norman, Global President, Golin Ketchum
• Jillian Janaczek, Americas CEO, FleishmanHillard

Why it matters in the category

Omnicom's acquisition of IPG created the largest marketing and communications holding company in the world, surpassing WPP. The PR portfolio inside OPRG now competes with WPP's Burson and Publicis Groupe's MSL across the global enterprise PR category. The full documentation of the six-to-three holding company consolidation is at The PR Agency Consolidation Study 2026. Where the AI engines rank Omnicom against the rest of the category: The Communications Holding Company Reputation Index 2026 and EPR GEO Scorecard Vol. 7 (Omnicom scores 74, B, second behind Publicis).

Deeper reading on Everything-PR

• The PR Industry Map, the canonical EPR reference on the global holdcos, leading independents, and AI Communications challengers.
• Omnicom Public Relations Group (OPRG), the full profile of Omnicom's PR subsidiary, its four cornerstone networks, and the February 2026 restructuring.
• The PR Agency Consolidation Study 2026, how the Big Six became three.
• The Communications Holding Company Reputation Index 2026 and EPR GEO Scorecard Vol. 7, how the AI engines rank Omnicom against Publicis, WPP, Dentsu, Havas, and S4 Capital.
• PR Holding Companies category hub
• Holdco profiles: WPP · Publicis Groupe · Dentsu Group · Havas Group · Stagwell Inc. · Inside IPG (historical) · S4 Capital
• Compensation: John Wren Made Nearly $70 Million in 2025 · Omnicom CEO Pay Ratio 1,219:1 · PR Executive Compensation Index 2026 · Highest-Paid CEOs in PR
• Inside IPG: Historical Profile · The Publicis-Omnicom Merger (2013/2025)
• History: PR Holding Company Profits and Losses: The 2015 Snapshot · PR Holding Companies and Public Affairs: The 2026 Political Engagement Map