Port Sinister (a.k.a. Beast of Paradise Isle in the UK) is a 1953 American independently made black-and-white adventure science fiction film, produced by Jack Pollexfen and Albert Zugsmith, and directed by Harold Daniels. The film was written by Jack Pollexfen and Aubrey Wisberg and stars James Warren, Lynne Roberts, and Paul Cavanagh. Port Sinister was theatrically distributed by RKO Radio Pictures. The film's storyline involves the 17th-century Caribbean city of Port Royal in the mid-20th century.