Uvs Lake Basin is an endorheic basin located on the territorial border of Mongolia and Tuva, a republic of the Russian Federation. The basin is part of the Central Asian Internal Drainage Basin and is named after Uvs Lake, a large saline lake situated in the western part of its drainage basin, and is one of the last remnants of the mammoth steppes. Uvs Lake is a shallow lake with an area of 3,350 km2 (1,290 sq mi). Its entire basin, which includes several smaller lakes, is 70,000 km2 (27,000 sq mi).

An endorheic basin is a drainage basin that normally retains water and allows no outflow to other, external bodies of water ; instead, the water drainage flows into permanent and seasonal lakes and swamps that equilibrate through evaporation. Endorheic basins are also called closed basins, terminal basins, and internal drainage systems.