'Requiem' is a short story by American writer Robert A. Heinlein, a sequel to his science fiction novella 'The Man Who Sold the Moon', although it was in fact published several years earlier than that story, in Astounding, January 1940. The story was also performed as a play on October 27, 1955, on the NBC Radio Network program X Minus One.

It is also the first story in the retrospective Requiem: New Collected Works by Robert A. Heinlein and Tributes to the Grand Master.