|This article does not cite any references or sources. (December 2009)|
|Location||Fiordland National Park, Southland District, Southland Region, South Island|
|Primary outflows||Wairaurahiri River|
|Basin countries||New Zealand|
|Max. length||40 km|
|Surface area||63 km²|
|Max. depth||463 m|
|Islands||1 (Mary Island)|
Lake Hauroko is located in a mountain valley in Fiordland National Park in the South Island of New Zealand. The long S-shaped lake is 30 kilometres in length and covers an area of 63 km². The surface is at an altitude of 150 metres above sea level, and the lake is 463 metres deep. It is New Zealand's deepest lake.
One of the country's southernmost lakes, it is 35 kilometres northwest of Tuatapere, between the similarly-sized lakes Monowai and Poteriteri. It drains via the 20 kilometre-long Wairaurahiri River into Foveaux Strait 10 kilometres to the west of Te Waewae Bay.
The main island on the lake, Mary Island, is the focus of several local myths, including one that the island is subject to a Māori curse. Such stories are dismissed by local Māori.