In Greek mythology, Stymphalus (Στύμφαλος) was a son of Elatus and Laodice, brother of Pereus, Aepytus, Ischys and Cyllen. He was the eponym of the town Stymphalus (now Stymfalia) and of a spring near it. Stymphalus' sons were Agamedes, Gortys (eponymous founder of Gortys, Arcadia) 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. 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.
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.
Stymphelus (Στύμφηλος, variant for Στύμφαλος) was mentioned in a late source as a son of Ares and Dormothea, who threw himself into the Arcadian river Nyctimus grieving over the death of his brother Alcmaeon, whereupon the river was renamed Stymphelus after him and bore this name until it was changed to Alpheus, allegedly after a descendant of Helios who too flung himself into the river to escape prosecution by the Erinyes over the murder of his brother Cercaphus.
- Pseudo-Apollodorus, Bibliotheca, 3. 9. 1; Pausanias, Description of Greece, 8. 4. 4
- Pausanias, Description of Greece, 8. 4. 6
- Pausanias, Description of Greece, 8. 4. 8
- Pausanias, Description of Greece, 8. 35. 9
- Pseudo-Apollodorus, Bibliotheca, 2. 7. 8
- Mnaseas in scholia on Apollonius Rhodius, Argonautica, 2. 1052
- Pseudo-Apollodorus, Bibliotheca, 3. 12. 6
- Pseudo-Apollodorus, Bibliotheca, 3. 8. 1
- Pseudo-Plutarch, On Rivers, 19. 1