Randall Garrett (1927–1987) was an American science fiction and fantasy writer known for his versatility, humor, and collaborations with other major genre authors. Writing during the Golden and Silver Ages of science fiction, he produced both serious speculative fiction and lighter, imaginative works.

Garrett helped popularize the blending of mystery and speculative fiction, particularly through the Lord Darcy stories, which influenced later fantasy mystery subgenres. He was also known for collaborations and contributions to shared science fiction universes.