river in southern North Island, New Zealand. It rises in the Tararua Range and, fed by the Pakuratahi, Mangaroa, Akatarawa, and Whakatikei rivers, flows south to enter Port Nicholson after a course of 35 miles (56 km). It supplies much of the fresh water used in the Wellington district.

The river valley, encompassing 250 square miles (650 square km) and known as Hutt, was settled under the auspices of the New Zealand Company in the 1840s and named for shareholder Sir William Hutt. It was previously an agricultural area but has become densely settled since the end of World War II. The valley is now a highly urbanized, industrialized part of the greater Wellington metropolitan area. It includes the cities of Lower Hutt and Upper Hutt and the boroughs of Petone and Eastbourne; Lower Hutt is the principal business and manufacturing centre.