The Arkhangai aimag is located in the interior of the country and borders to the following other aimags: Bulgan (north east), Övörkhangai (south east), Bayankhongor (south), Zavkhan (west), and Khövsgöl (north west).

The highest point is Kharlagtai Peak at 3,529 m (11,578 ft), while the lowest point is the area on the confluence of the Orkhon and Tamir rivers at 1,290 m (4,232 ft). The most well-known mountain is the extinct volcano Khorgo, which is part of the Khorgo-Terkhiin Tsagaan Nuur National Park.