Khalkhgol (, meaning Khalkha river) is a sum (district) of Dornod Province in eastern Mongolia. There are 3,203 people in the sum, including 1,756 in the sum center. The area of the sum is 28,093 km<sup>2</sup>, with a population density of 0.11 people/km<sup>2</sup>.
In 2018, the district received an â¬8 million donation from Russia to redevelop the district center. In 2019, the redevelopment project was completed, which consists of the governor's office, cultural center, hospital, secondary school and its students dormitory, kindergarten and a sport hall.
Khalkhgol is the largest district in Mongolia by land area. It is the easternmost district in both Dornod Province, and Mongolia as a whole.
Khalkhgol has a continental climate (Köppen climate classification Dwb) with warm summers and severely cold winters. Most precipitation falls in the summer as rain, with some snow in autumn and spring. Winters are quite dry, with occasional light snow.
The district is divided into three bags, which are: