Rumble Fish is a 1983 American drama noir film directed by Francis Ford Coppola. It is based on the 1975 novel Rumble Fish by S. E. Hinton, who also co-wrote the screenplay with Coppola. The film stars Matt Dillon, Mickey Rourke, Vincent Spano, Diane Lane, Diana Scarwid, Nicolas Cage, Laurence Fishburne, Chris Penn, and Dennis Hopper.

The film centers on the relationship between a character called the Motorcycle Boy (Rourke), a revered former gang leader wishing to live a more peaceful life, and his younger brother, Rusty James (Dillon), a teenaged hoodlum who aspires to become as feared as his brother.

Coppola wrote the screenplay for the film with Hinton on his days off from shooting The Outsiders. He made the films back-to-back, retaining much of the same cast and crew, particularly Matt Dillon and Diane Lane. Rumble Fish is dedicated to Coppola's brother August.

The film received positive reviews from critics, but was a box-office disaster, with its widest release earning a total of $2.5 million against an estimated budget of $10 million. It is notable for its avant-garde style with a film noir feel, shot on stark high-contrast black-and-white film, using the spherical cinematographic process with allusions to French New Wave cinema and German Expressionism. Rumble Fish features an experimental score by Stewart Copeland, drummer of the musical group The Police, who used a Musync, a new device at the time.

In Tulsa, Oklahoma, Rusty James is the younger brother of "The Motorcycle Boy", a legendary figure amongst the gangs in the area who brokered peace between them. The Motorcycle Boy has been missing for two weeks, leaving the gangs to start to dissolve as heroin takes over the streets, while Rusty James tries to live up to his reputation.

Rusty James fights a rival gang leader and gets the upper hand, but is distracted by the Motorcycle Boy's return, causing him to be wounded. The Motorcycle Boy runs the man down with his cycle before nursing Rusty James back to health. Rusty James's awkward, nerdy friend Steve helps the Motorcycle Boy, but is wary due to his rumored insanity similar to that of his long-absent mother. The brothers spend time with their impoverished, alcoholic father, who notes that the Motorcycle Boy takes after his mother.

Rusty James quits school after his fighting gets him suspended and cheats on his girlfriend Patty at a party hosted by his friend Smokey. She breaks up with him and Smokey accosts her, making Rusty James realize that the party was set up so Smokey could take advantage of the situation and date her. Steve and the brothers go drinking and the Motorcycle Boy mentions that he found his mother dating a television producer while out in California and laments not getting to see the Pacific Ocean. Steve and Rusty James are mugged as they leave a bar, and Rusty James is beaten to the point where he has a brief out-of-body experience. The Motorcycle Boy saves them and tries to convince Rusty James to leave the gang life, but Steve decries him as insane, which Rusty James starts to believe.

Rusty James finds the Motorcycle Boy in a pet store, where he is taken with the Siamese fighting fish (which he dubs "rumble fish" and are the only element of color in the film, as the Motorcycle Boy is colorblind). Patterson, a police officer who hates the Motorcycle Boy, regards them with suspicion. Rusty James's father tells him that the Motorcycle Boy and their mother are people with an "acute perception" rather than crazy.