Mysterious Island (UK: Jules Verne's Mysterious Island) is a 1961 science fiction adventure film about prisoners in the American Civil War who escape in a balloon and then find themselves stranded on a remote island populated by giant and tiny animals.

Loosely based upon the 1874 novel The Mysterious Island (L'Île mystérieuse) by Jules Verne (which was the sequel to two other novels by Verne, 1867's In Search of the Castaways and 1870's Twenty Thousand Leagues Under the Seas), the film was produced by Charles H. Schneer and directed by Cy Endfield.

Shot in Catalonia, Spain, and at Shepperton Studios, Shepperton, England, the film serves as a showcase for Ray Harryhausen's stop motion animation effects. Like several of Harryhausen's classic productions, the musical score was composed by Bernard Herrmann. Another version of the story was produced in 2005.