| Ōamaru River | |
| Mouth Location: | Mohaka River |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Length: | 17km (11miles) |
The Ōamaru River is a river of the centre of New Zealand's North Island. One of the headwaters of the Mohaka River, it flows generally northeast from its source 35km (22miles) southeast of Tūrangi, and forms the boundary between the Kaimanawa and Kaweka Forest Parks.