The Taramakau River is a river of the West Coast Region of the South Island of New Zealand. It rises in the Southern Alps / Kā Tiritiri o te Moana near Harper Pass, 80 kilometres (50 mi) due east of Hokitika, and runs westward for 75 kilometres (47 mi) into the Tasman Sea 15 kilometres (9.3 mi) south of Greymouth. The Taramakau River forms the administrative boundary between the Westland District to the south and the Grey District to the north.