Lake Wairarapa is a lake at the southern end of the North Island of New Zealand, 50 kilometres (31 mi) east of Wellington. The lake covers an area of 78 km (30 sq mi), and its maximum depth is 2.5 m (8.2 ft). It is the third largest lake in the North Island, fractionally smaller than Lake Rotorua (covering 79.8 km). The nearest town to the lake is Featherston, which is located five kilometres from its northern shore.
The lake forms part of the Wairarapa Moana Wetlands, a regional park administered by Wellington Regional Council, in collaboration with Kahungunu ki Wairarapa, the Department of Conservation, South Wairarapa District Council, and Rangitāne o Wairarapa. The wetland is the largest in the lower North Island, one of the largest in New Zealand, and was recognised as a wetland of international significance under the Ramsar Convention in August 2020.