Sin is a 1915 American silent drama film written and directed by Herbert Brenon and starring Theda Bara. It was produced by Fox Film Corporation and shot at the Fox Studio in Fort Lee, New Jersey. The film is now considered to be lost.
In order to play on Theda Bara's image as a "vamp", Fox Film Corporation publicized the film with the tagline "Sin With Theda Bara!". Upon its release, Sin was an enormous hit with audiences, and Bara earned generally good reviews for her performance. Despite its success in other locations, the film was banned in Ohio and Georgia for its themes of suicide, lust, Roman Catholic sacrilege, and love triangles. The Pittsburgh Board of Welfare condemned the film, as did the Kansas Board of Censorship, although the latter apparently still permitted screenings of the film in Kansas theaters.