Ōta River (太田川, Ōta-gawa) is a 103 kilometer (64 mile) long river in Hiroshima Prefecture, Japan. Its main stream originates in Mt. Kanmuri (冠山, Kanmuri-yama) (1,339m) and empties through a flood control channel into the Seto Inland Sea. The river is one of the major rivers in the prefecture and descends through steep topography, with hydroelectric power plants situated along the river. Ōta River has numerous tributaries and branches into the delta area of Hiroshima which comprises Tenma, Kyūōta/Honkawa, Motoyasu, Kyōbashi, and Enkō rivers.