Lake Wakatipu is an inland lake (finger lake) in the South Island of New Zealand. It is in the southwest corner of the Otago Region, near its boundary with Southland. Lake Wakatipu comes from the original Māori word Whakatipu wai-māori.

With a length of 80 kilometres (50 mi), it is New Zealand's longest lake, and, at 291 km (112 sq mi), its third largest. The lake is also very deep, its floor being below sea level, with a maximum depth of 380 metres (1,250 ft). It is at an altitude of 310 metres (1,020 ft), towards the southern end of the Southern Alps. The general topography is a reversed "N" shape or "dog leg". The Dart River flows into the northern end, the lake then runs south for 30 kilometres before turning abruptly to the east. Twenty kilometres (12.4 mi) further along, it turns sharply to the south, reaching its southern end 30 kilometres (19 mi) further south, near Kingston.