Coleman attended a Virginia military school before studying law and serving in the army. While attending the University of Texas, Coleman became attracted to acting, and headed to New York, where he studied at the Neighborhood Playhouse. After stage experience and TV work, Coleman made his movie debut in 1965's The Slender Thread. Minus his trademarked mustache for the most part in the mid-1960s, Coleman specialized in secondary character roles that were not outright villains, but somehow lacking in leading-man integrity. The first inkling that Coleman could handle comedy occurred during his supporting stint as obstetrician Leon Bessemer on the Marlo Thomas sitcom That Girl. In 1976, Coleman was cast as self-serving Mayor Jeeter (a role the actor still regards as a favorite) on Norman Lear's soap opera spoof Mary Hartman, Mary Hartman. Four years later, Coleman burst forth in full hissable glory as the nasty, chauvinistic boss in 9 to 5 (1980); he is so thoroughly trounced by Jane Fonda and Lily Tomlin and Dolly Parton in this film that one wonders how he was able to subsequently co-star with both Fonda and Tomlin in On Golden Pond  and The Beverly Hillbillies  respectively without flinching. After 9 to 5, Coleman's film roles became increasingly stereotyped; he was better served on television, where he starred in the ground-breaking sitcom Buffalo Bill (1983), playing TV's first thoroughly, unremittingly despicable "hero" and winning a nomination for a "Best Actor" Emmy. The series didn't last (audiences laughed at but did not love Buffalo Bill), but made enough of an impression for Coleman to ever afterward find himself playing cantankerous, mean-spirited sitcom leads; as recently as 1994, Coleman sneered his way through the starring role of a reactionary newspaper columnist in NBC's short-lived Madman of the People.