Campbell played "Animal" on the experimental FOX TV series Herman's Head, as well as Buckman in the 1996 movie Down Periscope. He appeared in the Seinfeld episode "The Seven," where he played Ken, the husband of Susan's first cousin, Carrie. He played "Bruce," the owner of an ominous bookstore in the 1997 Disney Channel film, Under Wraps. He appeared as oil driller Max Lennert in the film Armageddon, as the nice man in the hall in Groundhog Day, and was the voice of Baby Bob in the series Baby Bob and a series of Quiznos commercials that first aired in 2005.
Campbell was the voice of the beaver Gordon in the Canadian Bell Mobility phone commercials. He also now serves as one of the imaging voices for Cleveland, Ohio adult hits station WHLK "106.5 The Lake."