Wairau River
General data
- Name: Wairau River
- Water system: Pacific Ocean
- Water type: River
- Progression: Cloudy Bay -> Pacific Ocean -> Planet Earth
- Climates: Temperate
- Continents: Australia & Oceania
- Countries: New Zealand
The Wairau River is one of the longest rivers in New Zealand's South Island. It flows for 170 kilometres (110 mi) from the Spenser Mountains (a northern range of the Southern Alps), firstly in a northwards direction and then northeast down a long, straight valley in inland Marlborough.
The river's lower reaches and surrounding fertile plain provide the basis for the Marlborough wine region. The river has its outflow into Cook Strait at Cloudy Bay, just north of Blenheim in the island's northeast. The Wairau River meets the sea at the Wairau Bar, an important archaeological site.