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.

Edgar Rice Burroughs was an American writer, best known for his prolific output in the adventure, science fiction, and fantasy genres. Best known for creating the characters Tarzan and John Carter, he also wrote the Pellucidar series, the Amtor series, and the Caspak trilogy.