In Greek mythology, Sithon ( or ; ) was a king of the Odomanti or Hadomanti in Thrace, and presumably the eponym of the peninsula Sithonia and the tribe Sithones. He was the son of either Poseidon and Ossa or of Ares and Anchiroe, daughter of the river god Neilus. He was married to the nymph Mendeis, though Anchiroe is otherwise also given as his wife rather than mother, and had at least two daughters: Rhoeteia, eponym of the promontory of Rhoetium in the Troad, and Pallene. One source gives him as the father of the Thracian princess Phyllis, who loved Demophon of Athens.