Kiel broke into films in the early 1960s with Eegah (1962), which was later featured on Elvira's Movie Macabre and Mystery Science Theater 3000, as were The Phantom Planet and The Human Duplicators. He also produced, co-wrote, and starred in The Giant of Thunder Mountain. Kiel appeared as the towering — and lethal — assistant Voltaire to Dr. Miguelito Loveless in first-season episodes of The Wild, Wild West. He later appeared in the episode "The Night of the Simian Terror" as Dimas, the outcast son of a wealthy family, banished because of birth defects that distorted his body and apparently affected his mind. This episode is significant because it allowed Kiel the opportunity to really act rather than just look intimidating. Kiel also had a cameo role in a 1961 episode of The Rifleman.
From 1963 to 1965, Kiel worked as a night school math instructor in Burbank, California.
In the Man from U.N.C.L.E. episode "The Vulcan Affair", Kiel appeared as a guard in Vulcan's plant, and he portrayed Merry in "The Hong Kong Shilling Affair". In 1967 he played a Monster in an episode of The Monkees ("I was a Teenage Monster").
The James Bond-film producers spotted Kiel in Barbary Coast, and thought he was ideal for the role of Jaws in The Spy Who Loved Me (1977). He was one of the few Bond-villains to appear in two Bond-films, later appearing in Moonraker (1979). He reprised his role of Jaws in the video game called James Bond 007: Everything or Nothing, supplying his voice and likeness. Prior to becoming Jaws, Kiel gave a similarly menacing performance as another metal-toothed villain, Reace, in Silver Streak (1976).
In 1992, Kiel suffered a severe head injury in a car accident, which affected his balance. He was subsequently forced to walk with a cane to support himself (as shown in his appearance in Happy Gilmore, where he is seen leaning on a person or a cane). Later, Kiel used a scooter or wheelchair.
While Kiel's roles as Jaws and Reace offered him little dialogue, his role in Happy Gilmore (1996) was quite the opposite. As Mr. Larson, Happy Gilmore's former employer, Kiel exchanges several one-liners with both Adam Sandler's Happy and Christopher McDonald's Shooter. Kiel took a quieter profile after Happy Gilmore's release, but left semi-retirement to record a role for Tangled (2010). In the acclaimed animated Disney film, he portrayed Vlad, a surprisingly soft-hearted thug who collects ceramic unicorns.
On September 10, 2014, three days short of his 75th birthday, Kiel died at St. Agnes Medical Center in Fresno, California, of a heart attack, possibly caused by coronary artery disease.
