The Day the Earth Stood Still is a 2008 American science fiction film serving as remake of the 1951 film of the same name. Directed by Scott Derrickson from a screenplay by David Scarpa, it stars Keanu Reeves as Klaatu, an alien sent to try to change human behavior in an effort to save Earth from environmental degradation; this version replaces the Cold War-era theme of nuclear warfare with the contemporary issue of negative human impact on the environment. It co-stars Jennifer Connelly, Jaden Smith, John Cleese, Jon Hamm, and Kathy Bates.

The Day the Earth Stood Still is a 1951 American science fiction film from 20th Century Fox, produced by Julian Blaustein and directed by Robert Wise. It stars Michael Rennie, Patricia Neal, Hugh Marlowe, Sam Jaffe, Billy Gray, Frances Bavier and Lock Martin. The screenplay was written by Edmund H. North, based on the 1940 science fiction short story "Farewell to the Master" by Harry Bates. The film score was composed by Bernard Herrmann. Set in the Cold War during the early stages of the nuclear arms race, the storyline involves a humanoid alien visitor who comes to Earth, accompanied by a powerful robot, to deliver an important message that will affect the entire human race. In 1995, the film was selected for preservation in the United States National Film Registry as "culturally, historically, or aesthetically significant".