Peace on Earth is a one-reel 1939 Metro-Goldwyn-Mayer cartoon short directed by Hugh Harman, about a post-apocalyptic world populated only by animals, as it is claimed in the short that human beings have gone extinct due to war.

Two young squirrels ask their grandfather (voiced by Mel Blanc) on Christmas Eve who the "men" are in the lyric "Peace on Earth, good will to men." The grandfather squirrel then tells them a history of the human race, focusing on the never-ending wars men waged. Ultimately the wars do end, with the deaths of the last men on Earth, two soldiers shooting each other, one shoots the other soldier and the injured soldier kills the last, but slowly dies as he sinks into a watery foxhole while his hand grasps into the water. Afterwards, the surviving animals discover a copy of an implied Bible in the ruins of a church. Inspired by the book's teachings, they decide to rebuild a society dedicated to peace and nonviolence (using the helmets of the soldiers to construct houses). The short features a version of "Hark! The Herald Angels Sing" with rewritten lyrics, and a trio of carolers sing this song outside of the squirrels' house.

According to Hugh Harman's obituary in The New York Times^[2] and Ben Mankiewicz, host of Cartoon Alley, the cartoon was nominated for a Nobel Peace Prize.^[3] However, it is not listed in the official Nobel Prize nomination database.^[4] Mankiewicz also claimed that the cartoon was the first about a serious subject by a major studio. In 1994, it was voted #40 of the 50 Greatest Cartoons of all time by members of the animation field.^[5]

It was also nominated for the 1939 Academy Award for Short Subjects (Cartoons). It did not claim that honor (which instead went to Walt Disney's Silly Symphony The Ugly Duckling).

Fred Quimby, William Hanna and Joseph Barbera remade the cartoon in CinemaScope in 1955.^[3] This post-World War II version of the film, entitled Good Will to Men, featured updated and even more destructive forms of warfare technology such as flamethrowers, bazookas, missiles, and nuclear weapons.^[7] This version used a choir of mice as the main characters including a deacon mouse who tells the story to his charges, and also had more direct religious references (though the Bible is simply referred to as "the book of humans' rules" in both), Good Will to Men includes a reference to the New Testament, while Peace on Earth only includes verses from the Old Testament). This new version was also nominated for the Best Animated Short Subject Oscar, but lost to Speedy Gonzales. This film would be the last animated production for producer Fred Quimby before his retirement in May 1955.

Both Peace on Earth and Good Will to Men are included, digitally restored and uncut, on the Warner Bros. Home Entertainment Academy Awards Animation Collection DVD set. Peace on Earth is also included as an extra on The Mortal Storm Blu-Ray by Warner Archive Collection.

• List of Christmas films