Khar Us Nuur National Park (Mongolian: Хар Ус нуурын байгалийн цогцолборт газар, romanized: Khar Us nuuriin baigaliin cogcolbort gazar) is a national park in Khovd Province, Mongolia.

Khar-Us is fed by the Khovd Gol (River), which enters in a delta on the west side.

Birds include the endangered White-headed duck (Oxyura leucocephala), the near-threatened Dalmatian pelican (Pelecanus crispus) (formerly breeding in the park, but lately only passing through), and the vulnerable Swan goose (Anser cygnoides).

There are three species of endemic fish, including the Narrow-headed Altai osman (Oreoleuciscus angusticephalus).

in the 1960s, muskrat (Ondatra zibethicus) were introduced to the area for fur production; they have grown in number and place pressure on the reed beds.