Tsogt-Ovoo (Mongolian: Цогт-Овоо, mighty Ovoo) is a sum (district) of Ömnögovi Province in southern Mongolia.

As of 2009 the population of the sum was 1,666, including 619 in the sum center.

The area of the sum is 6,526 square kilometres (2,520 sq mi) and its population density is 0.26 people/km².

[1] Tsogt-Ovoo has a cold desert climate (Köppen climate classification BWk) with very warm summers and very cold winters.

Most precipitation falls in the summer as rain.