Choibalsan (Mongolian: Чойбалсан) is the fourth-largest city in Mongolia. The name of the city was Bayan Tu'men (Баян Түмэн) until 1941, when it was renamed after the communist leader Khorloogiin Choibalsan. It is the capital of the province of Dornod. The city administrative unit's official name is Kherlen sum, with area of 281 km².