| Tāngarākau River | |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Subdivision Type2: | Region |
| Subdivision Name2: | Manawatū-Whanganui |
| Subdivision Type3: | Settlements |
| Subdivision Name3: | Tāngarākau |
| Length: | 94km (58miles) |
| Source1 Location: | 8km (05miles) west of Ōhura |
| Source1 Elevation: | 470m (1,540feet) |
| Mouth Location: | Whanganui River |
| Mouth Elevation: | 85m (279feet) |
| Progression: | Tāngarākau River → Whanganui River |
| River System: | Whanganui River |
The Tāngarākau River is a river of the Manawatū-Whanganui region of New Zealand's North Island. It flows south for 94km (58miles) from its source 8km (05miles) west of Ōhura in the King Country to reach the Whanganui River.State Highway 43, known as the Forgotten World Highway, travels through the Tāngarākau Gorge.
As the river flows mainly through remote areas there are only five bridges across the river along its entire length.