Teenage Caveman (also known as Out of the Darkness in the United Kingdom) is a 1958 American independent black-and-white science fiction adventure film produced and directed by Roger Corman, and starring Robert Vaughn and Darah Marshall. The film was released by American International Pictures in July 1958 as a double feature with How to Make a Monster.

Originally filmed as Prehistoric World with some 8x10 publicity stills retaining this title, AIP later changed it. Years later, Corman stated in an interview, "I never directed a film called Teenage Caveman." Vaughn stated in an interview that he considered Teenage Caveman to be the worst film ever made. It was later featured on the mocking television series Mystery Science Theater 3000.