In Greek mythology, Phylacus founded the city of Phylace, Thessaly. He was the son of Deioneus and Diomede, husband of Clymene (Periclymene), and the father of Iphiclus and Alcimede. His children and grandchildren are sometimes referred to by the patronymic Phylacides. His grandson through Iphiclus was also named Phylacus.