In Greek mythology Cephissus also spelled Kephissos (/ˈkɛfɪˌsəs/ or /ˌkɪfɪˈsoʊs/; Ancient Greek: Κηφισός, romanized: Kephisos) is a river god of ancient Greece, associated with the river Cephissus in Attica and/or with the river Cephissus in Boeotia, both in Greece.