| Otamatea River | |
| Source1 Location: | Ahimanawa Range |
| Mouth Location: | Rangitaiki River |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Length: | 27km (17miles) |
| Mouth Elevation: | 622m (2,041feet) |
The Otamatea River is a river of the northwestern Hawke's Bay region of New Zealand's North Island. It flows generally north from its origins in the northern foothills of the Ahimanawa Range, reaching the Rangitaiki River 25 kilometres southwest of Taupō amid the Kaingaroa Forest.