Bayan-Ölgii is the westernmost of the 21 aimags (provinces) of Mongolia. The country's only Muslim and Kazakh-majority aimag, it was established in August 1940. Its capital is Ölgii.Shares borders with both Russia and China.

The culture of the Kazakh majority is strongly influenced by Islamic traditions. Bayan-Ölgii is the place, where an estimated 80 percent of the world's eagle hunters live.

The annual Golden Eagle Festival is held in Ölgii every October to display the skill of eagle hunters, with about 70 hunters participating per year.

The Altai Tavan Bogd National Park, National Park located in Bayan-Olgii aimag.  Covers 6,362 km² and is located south of the highest mountain of Mongolia.