1. A river-god in Bithynia, one of the sons of Oceanus and Thetys. (Hes. Theog. 340; Hom. Il. xii. 21; comp. Strab. xiii. p. 590.)

2. A son of king Eïoneus in Thrace, and an ally of the Trojans in their war with the Greeks. He possessed horses white as snow and swift as the wind, which were carried off by night by Odysseus and Diomedes, the latter of whom murdered Rhesus himself in his sleep (Hom. Il. x. 435, 495, &c.; Virg. Acn. i. 469, with Serv. note). In later writers Rhesus is described as a son of Strymon and Euterpe, or Calliope, or Terpsichore. (Apollod. i. 3. § 4; Conon, Narrat. 4; Eustath. ad Hom. p. 817; Eurip. Rhesus.)