The Pleasant River is in the Otago region of New Zealand. It rises in hilly forested country near Mount Trotter, west of Palmerston, fed by many small streams. After flowing generally eastward, the river turns south about 2 kilometres (1.2 mi) south of Palmerston, passes the settlement of Wairunga, and enters the sea via an estuary midway between Shag Point and Waikouaiti.

The mouth of the Pleasant River forms the administrative border between the Waitaki District and Dunedin City.