The Hikuwai River is the name for the middle section of the Ūawa River in the Gisborne Region of New Zealand. The river flows south through a valley between two hill ridges to the north of Tolaga Bay, and for most of its length runs parallel with the Pacific coast, which lies 5 kilometres (3 mi) to the east. The Hikuwai river section ends at the confluence with the Mangatokerau River 10 kilometres (6 mi) before the Ūawa River into the sea at Tolaga Bay.

In March 2022, heavy rainfall in the region caused the river to rise by over 9.6 metres, causing the nearby town of Mangatuna to be evacuated.

• List of rivers of New Zealand

"Place name detail: Hikuwai River". New Zealand Gazetteer. New Zealand Geographic Board. Retrieved 12 July 2009.

38°18′13″S 178°15′25″E / 38.303623°S 178.256919°E / -38.303623; 178.256919