Stymphalus was a son of Elatus and Laodice, brother of Pereus, Aepytus, Ischys and Cyllen. Stymphalus' sons were Agamedes, Gortys and Agelaus, himself father of Phalanthus who reputedly gave his name to a homonymous mountain and a city; Stymphalus also had at least one daughter, Parthenope, the mother of Everes by Heracles.
Stymphalus was treacherously killed by Pelops, who, being unable to defeat him at war, pretended to establish friendship with him, only to approach and slay the inadvertent Stymphalus; he then chopped off his limbs and scattered them around. As punishment for Pelops' crime, the gods had Greece suffer from infertility until the pious Aeacus was asked to pray for relief of the calamity.
A "rationalized" version of a myth of the Stymphalian birds names "a certain hero" Stymphalus and a woman Ornis (literally "bird") as parents of a set of daughters, the Stymphalides, who were killed by Heracles over the fact that they denied him hospitality but received the Molionidae.