Back River may refer to various watercourses:
Australia Back River (Tamworth), a tributary of the Barnard River in New South Wales Back River (Cooma-Monaro), a tributary of the Tuross River in New South Wales Back River (Victoria), a tributary of the Timbarra River in Victoria
Canada Back River (Nunavut) Rivière des Prairies in Quebec, also known in English as Back River Atlatzi River, British Columbia, formerly known as the Back River
Jamaica Back River (Jamaica)
United States Back River (Kennebec River), a river in coastal Maine, in the combined estuary of the Sheepscot and the Kennebec rivers Back River (Sheepscot River), a short tidal channel in the town of Boothbay, Maine Back River (Meduncook River), a short tributary of the Meduncook River in Friendship, Maine Back River (Medomak River), river in Friendship, Maine, which empties into the estuary of the Medomak River Back River (Saint George River), a tributary of the Saint George River in Knox County, Maine Back River (Maryland), a tidal estuary in Baltimore County, Maryland Back River (Powwow River), a tributary of the Powwow River in New Hampshire and Massachusetts Back River (Buzzards Bay), a small tidal estuary in Bourne, Massachusetts Back River (Massachusetts Bay), which flows into Duxbury Bay Back River (Merrimac, Massachusetts), a much smaller tributary of the Powwow River Weymouth Back River, in Weymouth, Massachusetts Back River (Berkeley County, South Carolina), a small tributary of the Cooper River (South Carolina) Back River (Virginia), an estuarine inlet of the Chesapeake Bay between Hampton and Poquoson, Virginia Back River (Savannah River), a secondary channel of the Savannah River, southeastern US