The à Âtira River is located in the central South Island of New Zealand. It rises on the slopes of Mount Rolleston in the Southern Alps, and flows north for , passing through the town of Otira before joining the Taramakau River. The Taramakau's outflow is into the Tasman Sea, south of Greymouth.
The valley of the à Âtira River forms the northwestern approach to Arthur's Pass, one of the three main passes across the Southern Alps.