The Hopkins River is in the central South Island of New Zealand. It flows south for 45 km from the Southern Alps / Kā Tiritiri o te Moana into the northern end of Lake Ōhau in the Mackenzie Country. Its headwaters, on the southern slopes of Mount Hopkins, form the northernmost point of Otago, and the river's braided valley is part of the border between Otago and Canterbury. The river's main tributary is the Dobson River.