Gannan Tibetan Autonomous Prefecture (; ) is an autonomous prefecture in southern Gansu Province, China, bordering Linxia to the north, Dingxi to the northeast, Longnan to the east and Aba (Sichuan province) to the south. It includes Xiahe and the Labrang Monastery, Luqu, Maqu and other mostly Tibetan towns and villages. Gannan has an area of and its capital is Hezuo city (Zoi). In the first year of the proclamation of Gannan Autonomous District, the district-seat was at the Labrang Town of Sangqu.
According to the 2010 census, Gannan has 689,132 inhabitants (population density: 17.14 inhabitants per km<sup>2</sup>).
Highway G213 runs through this prefecture. In 2013, the Gannan Xiahe Airport was opened.
1 county level city, 7 counties.
Gannan, as illustrated by this chart for Xiahe, has an alpine subarctic climate (Köppen Dwc) that grades into an alpine climate (ETH) at the highest elevations. The climate is characterised by mild, rainy summers and frigid, but dry and sunny, winters.