The River Seaton is a river in east Cornwall, England, UK which flows southwards into the English Channel.
The river rises near Caradon Hill and flows generally south past Darite, Menheniot and Hessenford and a few miles farther south into the sea at Seaton Beach, west of Downderry.
There is an early record of the river as "Seythyn" in 1302; the name means "little arrow river".
Coordinates: 50°21′49″N 4°23′16″W / 50.3635°N 4.3878°W