Menoetius or Menoetes (; Greek: Μενοίτιος, Μενοίτης Menoitios), meaning doomed might, is a name that refers to three distinct beings from Greek mythology:
- Menoetius, a second generation Titan, son of Iapetus and Clymene or Asia, and a brother of Atlas, Prometheus and Epimetheus, Menoetius was killed by Zeus on Mount Triphyle with a flash of lightning in the War of the Titans, and banished to Tartarus. His name means "doomed might," deriving from the Ancient Greek words menos ("might, power") and oitos ("doom, pain"). Hesiod described Menoetius as hubristic, meaning exceedingly prideful and impetuous to the very end. From what his name suggests, along with Hesiod's own account, Menoetius was perhaps the Titan god of violent anger and rash action.
- Menoetius, guard of the cattle of Hades. During Heracles twelfth labor, which required him to steal the hound Cerberus from the Underworld, he slays one of Hades cattle. A certain Menoetius, son of Keuthonymos, challenges Heracles to a wrestling match during which Heracles hugs him and breaks his ribs before Persephone intervenes.
- Menoetius, one of the Argonauts. He was the father of Patroclus and Myrto (by either Sthenele, Periopis or Polymele), son of Actor and Aegina.