| Wainui River | |
| Name Etymology: | Maori meaning "large waters" |
| Pushpin Map: | New Zealand |
| Pushpin Map Size: | 300px |
| Subdivision Type1: | Country |
| Subdivision Name1: | New Zealand |
| Subdivision Type2: | Region |
| Subdivision Name2: | Manawatū-Whanganui |
| Subdivision Type3: | District |
| Subdivision Name3: | Tararua |
| Subdivision Type4: | Settlements |
| Subdivision Name4: | Wimbledon |
| Length: | 28km (17miles) |
| Source1: | Mount McCartie |
| Mouth: | Pacific Ocean |
| Mouth Location: | Herbertville |
| Mouth Coordinates: | -40.4973°N 176.5602°W |
| Mouth Elevation: | Sea level |
The Wainui River is a river of the Tararua District in the Manawatū-Whanganui Region of New Zealand's North Island. It rises on Mt McCartie and flows approximately 28km (17miles) southeast through isolated hill country to reach the Pacific coast at Herbertville, five kilometres west of Cape Turnagain. The name Wainui means large waters. It is derived from the Maori words wai meaning water and nui meaning large.[1]
The Wainui River has a number of small tributary streams. Tributaries include (west to east): Angora Stream, Wimbledon Stream, Waikopiro Stream, Mangaone Stream, Mangaohau Stream, Tapui Stream, and Wairauka Stream.[2] [3]