Lake Taupō (also spelled Taupo; Māori: Taupō-nui-a-Tia or Taupōmoana) is a large crater lake in New Zealand's North Island, located in the caldera of the Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's northeastern shore. With a surface area of 616 km² (238 sq mi), it is the largest lake by surface area in New Zealand, and the second largest freshwater lake by surface area in geopolitical Oceania after Lake Murray in Papua New Guinea. Motutaiko Island lies in the southeastern area of the lake.

Lake Taupō has a perimeter of approximately 193 km (120 mi) and a maximum depth of 186 m (610 ft). It is drained by the Waikato River (New Zealand's longest river), and its main tributaries are the Waitahanui River, the Tongariro River, and the Tauranga Taupō River. It is a noted trout fishery with stocks of introduced brown and rainbow trout.

The level of the lake is controlled by Mercury Energy, the owner of the eight hydroelectric dams on the Waikato River downstream of Lake Taupō, using gates built in 1940–41. The gates are used to reduce flooding, conserve water and ensure a minimum flow of 50 m³/s (1,800 cu ft/s) in the Waikato River. The resource consent allows the level of the lake to be varied between 355.85 and 357.25 metres (1,167.5 and 1,172.1 ft) above sea level.