In Greek mythology, Caeneus was originally a Thessalonian woman (named Caenis), raped by Poseidon, who then fulfilled her request to be changed into a man so that she could never be raped again; he also made Caeneus invulnerable to weaponry. She changed her name to Caeneus and became a warrior who took part in the hunt for the Calydonian Boar. He died in the battle between the Lapiths and the centaurs (See Pirithous), who piled tree trunks upon him since he was immune to weapons. He flew away from the pile of tree trunks as a bird. Alternatively, he changed back into a woman after death and was buried as a female.

Caeneus had one son, Coronus.

Ovid, Metamorphoses VIII, 305; IX, 171-209 & 459-525; Apollodorus, Epitome I, 22.