Peleus was the son of Aeacus, King of Aegina. He was one of the Argonauts who accompanied Jason on the quest for the Golden Fleece. His most famous son was Achilles.

Peleus and his brother Telamon killed their half-brother, Phocus, and had to flee Aegina. Peleus went to Phthia, where he was purified of his crime by Eurytion and married Eurytion's daughter, Antigone. When he and Eurytion participated in the Calydonian boar hunt, however, Peleus accidentally killed Eurytion with a spear during the hunt, and had to flee Phthia.

He went to Iolcus, where he was purified of this second homicide by Acastus, the country's new king. In Iolcus, Peleus participated in the funeral games of Acastus' father, Pelias, and lost a wrestling match with Atalanta, the maiden warrior and huntress. Acastus' wife, Astydameia, fell in love with Peleus, but he repulsed her advances; she sent a message to his wife, Antigone, telling her that Peleus was to marry the daughter of Acastus, and Antigone hanged herself.

Astydameia also told her husband that Peleus had attempted to seduce her; Acastus then took Peleus on a hunting trip, hid his sword, and abandoned him. The Centaurs attacked Peleus and would have overwhelmed him, but Chiron (one of the Centaurs) returned the sword and Peleus repulsed the attack. Peleus got his revenge by attacking and pillaging Iolcus and then killing Astydameia; he dismembered her body and marched his army between the pieces.

After Antigone's death, Peleus married the Nereid Thetis. All the gods attended the wedding and brought magnificent gifts, including armor made by Hephaestus and a pair of immortal horses from Poseidon. Thetis and Peleus had a son, Achilles; Thetis deserted the marriage after Peleus interrupted her attempt to make the infant immortal by placing it on a fire. Peleus then placed Achilles in the care of the Centaur Chiron, who raised him.

There are differing accounts of the end of Peleus' life. In one, the sons of Acastus expelled him from Phthia and he died. In another, he was reunited with Thetis and became immortal.