
Sawyer has headed the agency, which works for clients including Nike, Disney and Delta Airlines, since 2001.
In a statement, Dave Luhr, Wieden & Kennedy's global chief operating officer, said Sawyer had been a "true pillar" of the agency.
In an earlier stint at W&K, Sawyer opened its first international office in Amsterdam, and was managing director for six years.
W&K recently hired Poke's founding partner Iain Tait to the role of global interactive executive creative director.