"Later Than You Think" is a short story by Fritz Leiber. It was first published in Galaxy Science Fiction in October 1950.

Fritz Leiber was one of science fiction's prolific short story writers in the Golden Age and New Wave eras. He was nominated for numerous awards, including 13 Hugos and 11 Nebulas. He won six and three, respectively, all for novellas and short stories.

Leiber went on to become the fifth Grand Master of the Science Fiction & Fantasy Writers of America, and he's even said to have invented the term "Sword and Sorcery." He remains one of the most influential science fiction and fantasy writers of his time.