Nøklevann is a lake in Østmarka in Oslo, Norway. It has a surface area of 0.8 km², and is 163 meters above sea level. The lake drains through Ljanselva to Bunnefjorden. It is a former drinking water supply for Oslo.
Coordinates: 59°52′31″N 10°52′37″E / 59.87528°N 10.87694°E / 59.87528; 10.87694