Khar-Us Lake (Mongolian: Хар-Ус нуур, ᠬᠠᠷ᠎ᠠᠤᠰᠤᠨᠠᠭᠤᠷ, lit.

"black water lake", Chinese: 哈尔乌斯湖, 黑水湖) is a lake located in western Mongolia in the Uvs Province between the districts of Ömnögovi and Ölgii.

Khar-Us Lake is located south of the city of Ulaangom and about 80 km (50 mi) north of the homonymous and larger Khar-Us Lake in the Khovd Province.

The warmest month is July, at 21 °C, and the coldest is January, at -22 °C.

This article related to a lake in Mongolia is a stub.