The Ahuriri River is in Otago, in the South Island of New Zealand.

The headwaters are on the eastern flanks of the Southern Alps. The river flows for 70 kilometres through the southernmost part of the Mackenzie Basin before reaching Lake Benmore, one of the lakes in the Waitaki hydroelectric project. From there, the waters join with those of the Waitaki, which has its outflow in the Pacific ocean.