Rebel Without a Cause is a 1955 American coming-of-age melodrama film, directed by Nicholas Ray. The film stars James Dean, Natalie Wood, Sal Mineo, Jim Backus, Ann Doran, Corey Allen and William Hopper. It is also the film debut of Dennis Hopper, albeit in a minor role. It was filmed in the then recently introduced CinemaScope format. Focusing on emotionally confused suburban, middle-class teenagers, the film offers both social commentary and an alternative to previous films depicting delinquents in urban slum environments.

The film was an attempt to portray the moral decay of American youth, critique parental styles, and explore the differences and conflicts between generations, namely the Interbellum Generation and the Silent Generation. The title was adopted from psychologist Robert M. Lindner's 1944 book, Rebel Without a Cause: The Hypnoanalysis of a Criminal Psychopath, although the film itself does not make any other references to Lindner's book. Warner Bros. released the film on October 27, 1955, nearly a month after Dean's death in a car crash on September 30, 1955.

Over the years, the film has achieved landmark status for the performance of Dean, fresh from his Oscar-nominated role in East of Eden, in his most celebrated role. This was the only film of Dean's in which he received top billing. In 1990, Rebel Without a Cause was added to the Library of Congress's National Film Registry as being deemed "culturally, historically, and aesthetically significant".