# Brian Lesser
> Global CEO, WPP Media at wpp media
- Profile type: Person
- Profile status: baseline
- Last updated: 2026-05-03T00:00:00.000Z
- Canonical URL: https://thestateofstreaming.com/people/brian-lesser/
- Also known as: Brian D. Lesser
## Summary
Global CEO of WPP Media, the agency holding company's media arm rebranded from GroupM in May 2025. A returning WPP executive — Lesser co-founded programmatic buyer Xaxis in 2011, ran GroupM North America, then left to lead AT&T's advertising business (later Xandr) and identity-data firm InfoSum before being recalled in 2024 to overhaul the world's largest media-buying group.

## Profile facts

- Current title: Global CEO, WPP Media
- Current company: wpp media (https://thestateofstreaming.com/companies/wpp-media/)


## Career trajectory

- 2007-01-01 — Executive (via 24/7 Real Media acquisition) at wpp. Joined WPP through its acquisition of 24/7 Real Media; later founded the Media Innovation Group inside GroupM.
- 2011-01-01 — Co-founder and CEO, Xaxis at xaxis. Co-founded Xaxis as GroupM's programmatic media-buying platform; now part of GroupM Nexus.
- 2015-11-01 — CEO, GroupM North America at wpp-media. Promoted to lead GroupM's largest regional business, overseeing six media agencies.
- 2017-01-01 — CEO, AT&T Advertising & Analytics (later Xandr) at at-and-t. Left WPP to lead AT&T's advertising unit, which became Xandr after AT&T's WarnerMedia acquisition; the unit was later sold to Microsoft.
- 2020-01-01 — Chairman and CEO, InfoSum at infosum. Joined the data-collaboration / identity firm; ran the company for roughly four years before returning to WPP.
- 2024-09-01 — Global CEO, GroupM at wpp-media. Returned to WPP to run GroupM globally, succeeding Christian Juhl.
- 2025-05-28 — Global CEO, WPP Media at wpp-media. Title transitioned with the GroupM-to-WPP Media rebrand; led the consolidation of agency brands under a single operating model anchored on the WPP Open AI platform.

_This page uses only public-professional information (roles, public statements, media appearances)._

## Key facts

- Appointed Global CEO of GroupM in July 2024, effective September 2024, succeeding Christian Juhl. — WPP: https://www.wpp.com/en/news/2024/07/wpp-appoints-brian-lesser-as-global-ceo-of-groupm
- Co-founded Xaxis in 2011 inside GroupM as the holding company's programmatic media-buying arm; the platform now sits within GroupM Nexus. — WPP: https://www.wpp.com/en/news/2024/07/wpp-appoints-brian-lesser-as-global-ceo-of-groupm
- Served as CEO of GroupM North America from 2015 to 2017 before leaving to run AT&T's advertising and analytics business, later rebranded Xandr. — Variety: https://variety.com/2024/tv/news/brian-lesser-global-ceo-groupm-wpp-1236075201/
- Was Chairman and CEO of identity-data firm InfoSum from 2020 until July 2024, when he resigned to return to WPP. — VideoWeek: https://videoweek.com/2024/07/17/infosums-brian-lesser-named-groupm-ceo/
- Confirmed the GroupM-to-WPP Media rebrand on May 28, 2025, telling staff the new structure consolidates the agency network around a single AI-powered operating model managing more than $60 billion in annual media investment. — The Drum: https://www.thedrum.com/news/2025/05/28/ceo-tells-staff-the-future-wpp-media-here-groupm-rebrand-confirmed


## Related

- wpp media (CEO) — https://thestateofstreaming.com/companies/wpp-media/
- wpp (operating-company-CEO) — https://thestateofstreaming.com/companies/wpp/
- xaxis (co-founder (historical)) — https://thestateofstreaming.com/companies/xaxis/
- at and t (former-executive) — https://thestateofstreaming.com/companies/at-and-t/
- infosum (former-CEO) — https://thestateofstreaming.com/companies/infosum/


## External coverage

- 2024-07-17 — WPP: WPP appoints Brian Lesser as Global CEO of GroupM (https://www.wpp.com/en/news/2024/07/wpp-appoints-brian-lesser-as-global-ceo-of-groupm)
- 2024-07-17 — Variety: WPP's GroupM Names Brian Lesser Global CEO (https://variety.com/2024/tv/news/brian-lesser-global-ceo-groupm-wpp-1236075201/)
- 2024-07-17 — VideoWeek: Infosum's Brian Lesser Named GroupM CEO (https://videoweek.com/2024/07/17/infosums-brian-lesser-named-groupm-ceo/)
- 2025-05-28 — The Drum: CEO tells staff 'the future of WPP Media is here' as GroupM rebrand confirmed (https://www.thedrum.com/news/2025/05/28/ceo-tells-staff-the-future-wpp-media-here-groupm-rebrand-confirmed)
- 2024-07-17 — Marketing Dive: WPP brings back data hotshot Brian Lesser to lead GroupM (https://www.marketingdive.com/news/wpp-appoints-brian-lesser-to-lead-groupm/721914/)

## Profile
Lesser is one of the few agency-world executives whose career has bracketed the rise of programmatic, the platform-era ad-tech consolidation, and the current scramble around identity and AI. His return to WPP in 2024 — and the speed with which he moved to collapse the GroupM brand into a single WPP Media operating model the following May — has put him on the short list of executives reshaping how the largest media-buying organizations interface with platforms, measurement vendors, and the AI stack.

## Tags

- executive
- agency-holding-companies
- programmatic
- identity
- data-clean-rooms

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