In 1973, Scott starred with Al Pacino on Broadway in Shakespeare's Richard III. His first film role was in Every Which Way But Loose (1978), in which he played a biker. His other films include I, the Jury (1982) and Escape (1990).

In the 1982 film Star Trek II: The Wrath of Khan, Scott played Joachim, chief henchman of Khan Noonien Singh. Despite having many lines of dialogue, Scott's name does not appear in the credits. According to TV Guide, Scott's agent was in negotiations with Paramount to get his name high billing in the movie, but the tactic backfired and somehow Scott wound up with no credit at all. He played opposite Ricardo Montalban, which resulted in a friendship that lasted until Montalban's death in January 2009. When Montalban received a lifetime achievement award in 2003, Scott was the presenter.

Other guest appearances include Mission: Impossible (as Ernst Graff in "The Legacy") Voyagers!, The Dukes of Hazzard, The A-Team, Babylon 5 (as "Knight One" in "And the Sky Full of Stars", 1994), Charmed (as "Necron" in episodes "A Witches Tale" 1 & 2) and The X-Files and The Greatest American Hero (as Dack Hampton in the episode "Rock 'n' Roll"). He also made three appearances on Matt Houston as a Navajo shaman turned Assassin.