Garrett O'Reilly

Garrett O'Reilly is a senior media and advertising executive serving as President of Hearts & Science, Omnicom's data-driven media agency launched in 2016 to serve clients including AT&T, P&G, and other major advertisers. He is recognized for driving the agency's strategic vision around data, analytics, and audience-first media planning in an era of accelerating digital transformation. His leadership has helped position Hearts & Science as one of the more analytically sophisticated agencies within the Omnicom Media Group portfolio. O'Reilly's career has been rooted in media agency operations, with a trajectory through Omnicom's network of agencies where he developed deep expertise in integrated media strategy, programmatic advertising, and data-driven decision-making. He has been instrumental in building out the agency's capabilities around advanced TV, digital media, and performance-oriented planning frameworks that align media investment with measurable business outcomes. As President, O'Reilly oversees agency operations, client relationships, and talent development, working to ensure Hearts & Science remains competitive in a rapidly evolving media landscape shaped by identity resolution challenges, the deprecation of third-party cookies, and the rise of retail media and connected TV. His influence spans both the operational and strategic dimensions of modern media agency leadership.

Last updated Jul 30, 2026 by ATDb automated enrichment · Connections updated Aug 3, 2026