Rasmussen, who left BBH New York in October last year, will be responsible with helping to raise Tribal DDB's creative profile in the US, working across a client list that includes Philips, Diageo and Jose Cuervo.
During his time at BBH New York, Rasmussen worked on high profile campaigns for Sprite and GMAC/Ally Bank.
Previous to working at the agency he spent time as executive creative director at R/GA, where he was responsible for overseeing all of the shop's Nike business, working on campaign's including Nike Plus Human Race and Head2Head.
Chuck Brymer, the president and chief executive of DDB Worldwide, said: "We're delighted to have Robert on board at Tribal DDB where he will continue to raise an already high creative bar and be a vital addition to the team."