Michael Rennie (born August 1909 – June 10, 1971) was an English actor best known for his role as Klaatu in the science fiction classic The Day the Earth Stood Still (1951). He enjoyed a successful career spanning film, television, and theater, gaining fame for his dignified and often authoritative roles.

Michael Rennie was born Eric Alexander Rennie in Ilford, Essex, England. His early interest in acting led him to the Royal Academy of Dramatic Art (RADA), where he trained and developed his skills as a performer. He worked initially in British theater before transitioning to film.