This Island Earth is a 1955 American science fiction film produced by William Alland, directed by Joseph M. Newman and Jack Arnold, and starring Jeff Morrow, Faith Domergue and Rex Reason. It is based on the 1952 novel of the same name by Raymond F. Jones. The film, distributed by Universal-International, was released in 1955 on a double feature with Abbott and Costello Meet the Mummy.

Upon initial release, the film was praised by critics, who cited the special effects, well-written script, and the eye-popping Technicolor as being its major assets. In 1996, it was edited down and lampooned in Mystery Science Theater 3000: The Movie, a spin-off of the popular film-riffing television series Mystery Science Theater 3000.

The 1952 novel by Jones was originally serialized in the science fiction magazine Thrilling Wonder Stories as three related novelettes: "The Alien Machine" (June 1949), "The Shroud of Secrecy" (December 1949), and "The Greater Conflict" (February 1950). Jones had taken the novel title from a line in Robert Graves' poem "Darien" ("It is a poet’s privilege and fate/To fall enamoured of the one Muse/Who variously haunts this island earth").