In Greek mythology, Endymion  was variously a handsome Aeolian shepherd, hunter, or king who was said to rule and live at Olympia in Elis. He was also venerated and said to reside on Mount Latmus in Caria, on the west coast of Asia Minor.

Apollonius of Rhodes is one of the many poets who tell how Selene, the Titan goddess of the moon, loved the mortal Endymion. She believed him to be so beautiful that she asked Endymion's father, Zeus, to grant him eternal youth so that he would never leave her. Alternatively, Selene so loved how Endymion looked when he was asleep in the cave on Mount Latmus, near Miletus in Caria, that she entreated Zeus that he might remain that way. In some versions, Zeus wanted to punish Endymion for daring to show romantic interest in Hera (much like Ixion). Whatever the case, Zeus granted Selene's wish and put Endymion into an eternal sleep. Every night, Selene visited him where he slept, and by him had fifty daughters who are equated by some scholars with the fifty months of the Olympiad.

The myth of Endymion was never easily transferred to ever-chaste Artemis, the Olympian associated with the Moon. In the Renaissance, the revived moon goddess Diana had the Endymion myth attached to her.