John Halley
Advisor at TWG Global
Halley is known for leading the operational and strategic transformation of Publicis Media's global media buying capabilities, particularly in programmatic advertising and data-driven audience solutions at holding company scale.
Last updated May 26, 2026 by the ATDb Editorial Team · Connections updated May 31, 2026
John Halley is an advertising and media executive, currently an Advisor at TWG Global. He spent more than six years at Paramount, most recently as President of Advertising (2022–2026), after a long tenure at Viacom where he served as Chief Operating Officer of Advertising. A prominent industry leader, Halley chaired the audience-data platform OpenAP for nine years and is a former Chair of the IAB, with board roles at the VAB and Blockgraph.
President, Advertising
Paramount (2022–2026)
Chief Operating Officer, Advertising
Viacom (2013–2019)
SVP, Ad Sales Finance & Operations
Viacom (2007–2013)
- Led Publicis Media as President overseeing a portfolio of major agency brands managing tens of billions in annual global media spend
- Drove integration of Epsilon data platform across Publicis Media agency brands to enable addressable advertising at scale
- Oversaw programmatic and AdTech capability buildout across Starcom, Zenith, and Spark Foundry