The People That Time Forgot is a 1977 adventure fantasy film based on the novel The People That Time Forgot (1918) and Out of Time's Abyss (1918) by Edgar Rice Burroughs. Filmed in Technicolor, it was produced by Britain's Amicus Productions and directed by Kevin Connor. Like Connor's other two Burroughs-derived films, The Land That Time Forgot and At the Earth's Core, the film was distributed in the United States by American International Pictures. It is the last film made by Amicus before the production company folded.

The People That Time Forgot is a fantasy novel by American writer Edgar Rice Burroughs, the second of his Caspak trilogy. The sequence was first published in Blue Book Magazine as a three-part serial in the issues for August, October, and December 1918, with The People That Time Forgot forming the second installment. The complete trilogy was later combined for publication in book form under the title of The Land That Time Forgot by A. C. McClurg in June 1924. Beginning with the Ace Books editions of the 1960s, the three segments have usually been issued as separate short novels.