Callen got his start as an original cast member of MAD TV. He then went on to play numerous roles on the small and big screen, including Old School, Bad Santa, The Hangover, Sex and the City, Entourage, Californication, 7th Heaven, King of Queens, Stacked, Las Vegas, West Wing, News Radio, Significant Others, CSI, NYPD Blue, Suddenly Susan, and Frasier. In 2012, he finished a two-season character arc on USA’s In Plain Sight.
Callen is not a famous actor, but sometimes people look at him and scream, “Bilson,” since that’s the character he played on several episodes of CBS’s How I Met Your Mother. In 2011, he played Captain Frank Dashell, leader of the Undead Task Force, in the short-lived but critically acclaimed MTV comedy, Death Valley.
His most recent TV appearances can be found on his recurring role as Coach Miller in The Goldbergs and Garo Kassabian in Kingdom.