The faun (Latin: faunus, Ancient Greek: φαῦνος, phaunos, pronounced [pʰaunos]) is a half-human and half-goat mythological creature appearing in Greek and Roman mythology.

Originally fauns of Roman mythology were spirits (genii) of rustic places, lesser versions of their chief, the god Faunus. Before their conflation with Greek satyrs, they and Faunus were represented as nude men (e.g. the Barberini Faun). Later fauns became copies of the satyrs of Greek mythology, who themselves were originally shown as part-horse rather than part-goat.

By Renaissance times fauns were depicted as bipedal creatures with the horns, legs, and tail of a goat and the head, torso, and arms of a human; they are often depicted with pointed ears. These late-form mythological creatures borrowed their appearance from the satyrs, who in turn borrowed their appearance from the god Pan of the Greek pantheon. They were symbols of peace and fertility, and their Greek chieftain, Silenus, was a minor deity of Greek mythology.