The Ahuriri River is a river in the Canterbury and Otago Regions of the South Island of New Zealand.
The headwaters are on the eastern flanks of the Southern Alps. The river flows for 70 kilometres (43 mi) through the southernmost part of the Mackenzie Basin before reaching the Ahuriri Arm of 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.