Khar-Us Lake (; ) is a lake in Khovd Province, Mongolia, located in Khar Us Nuur National Park. It is the upper one in a system of the interconnected lakes: Khar-Us, Khar, Dörgön, Airag and Khyargas.
Its area value (1,852 km<sup>2</sup>) includes the island Agbash (or Ak-Bashi, white head) area (274 km<sup>2</sup>), so the water surface area is 1,578 km<sup>2</sup> only.
Some sources are using different Khar-Us Lake Lake statistics values:
Primary inflow is the Khovd River, which creates a large river delta.
So called Genghis Khan's wall runs along the western shore of the Khar-Us Lake. It is possible to find it at the Google Map and Google Earth satellite maps .