The Sin Ship is a 1931 American pre-Code drama film produced and distributed by RKO Radio Pictures and directed by the actor Louis Wolheim in his only directorial effort. The film marks the last contribution Wolheim made to the film industry prior to his death from cancer one month shy of his fifty-first birthday. In addition to directing, Wolheim also starred in the picture, alongside Mary Astor and Ian Keith. The screenplay was written by Hugh Herbert, from a story by Keene Thompson and Agnes Brand Leahy. The film was released in April 1931, two months after Wolheim's death, and is preserved at the Library of Congress.

Louis Robert Wolheim was an American actor, of both stage and screen, whose rough physical appearance relegated him to roles mostly of thugs, villains and occasionally a soldier with a heart of gold in the movies, but whose talent allowed him to flourish on stage. His career was mostly contained during the silent era of the film industry, due to his death at the age of 50 in 1931.