Colonel John Casey (born Alexander Coburn) is portrayed by actor Adam Baldwin on the television show Chuck on NBC. Prior to the episode "Chuck Versus the Tic Tac," he was partnered with CIA agent Sarah Walker to protect Chuck Bartowski. He was dismissed again at the end of the season 4 "Chuck Versus the Cliffhanger", and was hired by Chuck and Sarah for their private spy operation. He left Carmichael Industries to pursue his love interest, Gertrude, in the series finale.