The Waipawa River is a braided river of southern Hawke's Bay, in New Zealand's eastern North Island.^[1] It flows southeast from the slopes of 1,687 m (5,535 ft) Te Atuaoparapara (once known as 'Sixty-six')^[2] in the Ruahine Range, past the town of Waipawa, before joining the Tukituki River.^[3] The river rises at the 1,326 m (4,350 ft) Waipawa Saddle, which is also the source of the Waikamaka River.^[4] The Mangaonuku Stream is a tributary on the northern bank, west of Waipawa, near Ruataniwha.^[5] The Waipawa's flow is generally greater than that of the Tukituki River, into which it flows.^[6]

The Old Bed of Waipawa River flows roughly parallel with and north of the present Waipawa River to join the Tukituki through the Papanui Stream, south west of Lake Poukawa.^[7] The Waipawa changed its course during a flood in 1868.^[8] It reverted to its old course during Cyclone Gabrielle in February 2023, until the Coronation Park stop bank in Waipawa was repaired on 16 February, returning the Waipawa to its post-1868 course.^[9]

River quality is sampled at the SH50 bridge. At that site its Macroinvertebrate Community Index is C (of grades A to D) and likely degrading, but it is in the best 25% of rivers for most samples, except clarity. In warm weather cyanobacteria sometimes develop.^[10] Other main routes crossing the river are SH2 and the Palmerston North–Gisborne railway at Waipawa.^[11]

There are hundreds of banded dotterel (pohowera) and pied stilt around the river.^[1]

Waipawa Forks Hut provides accommodation close to the headwaters of the river.^[12] On the ridge to the north, above the headwaters, is Sunrise Hut. It is the most popular hut in the Ruahine Park and was renovated in 2020.^[13] A day walk is possible, via Sunrise and the Saddle.^[14]