The Rocky Horror Picture Show is a 1975 independent musical comedy horror film produced by Lou Adler and Michael White, directed by Jim Sharman, and distributed by 20th Century Fox. The screenplay was written by Sharman and Richard O'Brien, who also played the supporting role Riff-raff. The film is based on the 1973 musical stage production The Rocky Horror Show, with music, book, and lyrics by O'Brien. The production is a tribute to the science fiction and horror B movies of the 1930s through to the early 1960s. The film stars Tim Curry, Susan Sarandon, and Barry Bostwick. The film is narrated by Charles Gray, with cast members from the original Royal Court Theatre, Roxy Theatre, and Belasco Theatre productions, including Nell Campbell and Patricia Quinn.

The story centres on a young engaged couple whose car breaks down in the rain near a castle, where they search for help. The castle is occupied by strangers in elaborate costumes holding a party. They then meet the head of the house: Dr. Frank N. Furter, an apparently mad scientist and alien transvestite from the planet Transsexual in the galaxy of Transylvania, who creates a living muscle man named Rocky.

The film was shot in the United Kingdom at Bray Studios and on location at an old country estate named Oakley Court, best known for its earlier use by Hammer Film Productions. A number of props and set pieces were reused from the Hammer horror films. Although the film is both a parody of and tribute to many kitsch science fiction and horror films, costume designer Sue Blane conducted no research for her designs. Blane has claimed that her creations for the film directly affected the development of punk rock fashion trends, such as torn fishnet stockings and colourfully dyed hair.

Initial reception was extremely negative, but it soon became a hit as a midnight movie, when audiences began participating with the film at the Waverly Theater in New York City in 1976. Audience members returned to the cinemas frequently and talked back to the screen and began dressing as the characters, spawning similar performance groups across the United States. At almost the same time, fans in costume began performing alongside the film. This "shadow cast" mimed the actions on screen above and behind them, while lip-synching their characters' lines.

Still in limited release in 2024, some 49 years after its premiere, it is the longest-running theatrical release in film history. In many cities, live amateur shadow-casts act out the film as it is being shown and heavily draw upon a tradition of audience participation. The film is most often shown close to Halloween. Today, the film has a large international cult following and has been considered by many as one of the greatest musical films of all time. In 2005, it was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant."