Guchin-Us (Mongolian: Гучин-Ус, meaning is Thirty water) is a sum (district) of Övörkhangai Province in southern Mongolia. It had an estimated 2,260 inhabitants in 2008.^[1]

The town of Arguut, 104 km from the Province capital Arvaikheer, is the administrative center of the soum, but mostly it is called "Guchin Us" as well.^[2]

There are several prehistoric rock paintings and buddhist inscriptions in the north-east of the town, close to the unpaved road to Arvaikheer.

45°27′42″N 102°25′27″E / 45.46167°N 102.42417°E / 45.46167; 102.42417