Townsend will lead strategic development, project delivery and cross-office collaboration on the account.
R/GA handles activity for Unilever’s Simple, St Ives, Citra, Rexona/Sure, Impulse, Axe/Lynx, Magnum and Closeup brands.
Townsend will report to Matt Lodder, the senior vice-president and managing director for EMEA, and replaces Iestyn Keyes, who has been promoted to managing director at R/GA Singapore.
Before joining Mcgarrybowen in 2014, Townsend spent six years at BBDO, handling the AT&T and BlackBerry businesses.
Lodder said: "This is a significant hire for the agency, curated to ensure we offer world-class strategic thought leadership to our most senior Unilever clients.
"Will taking the managerial reins of our global Unilever portfolio underlines our commitment to continue to evolve our global partnership and will ensure we continue to deliver culturally relevant work for a connected world."