TBWA\Chiat\Day (/ˈtʃaɪ.æt/ CHY-at) is the American division of the advertising agency TBWA Worldwide.
[1] The merger also inspired the creation of the ad agency St.Lukes by Chiat/Day's London office's employees.
[2] TBWA Worldwide is part of the global marketing group Omnicom, with a reputation for more quirky or "disruptive" work.
The youngest network in the group's portfolio, TBWA expanded rapidly in the final years of the 1990s and is a competitor to BBDO and DDB.
A significant step came in 1998 when the agency absorbed Anglo-French marketing network GGT BDDP.