Updated: January 09, 2024

Fantastic Voyage is a 1966 American science fiction film directed by Richard Fleischer and written by Harry Kleiner, based on a story by Otto Klement and Jerome Bixby. The film is about a submarine crew who shrink to microscopic size and venture into the body of an injured scientist to repair the damage to his brain.

The original story took place in the 19th century and was meant to be a Jules Verne–style adventure with a sense of wonder. Kleiner abandoned all but the concept of miniaturization and added a Cold War element. The film starred Stephen Boyd, Raquel Welch, Edmond O'Brien, and Donald Pleasence.

Bantam Books obtained the rights for a paperback novelization based on the screenplay and approached Isaac Asimov to write it. Because the novelization was released six months before the movie, many people mistakenly believed the film was based on Asimov's book.

The movie inspired an animated television series.