Zhidoi County (, ) is a county in the west and southwest of Qinghai Province, China, bordering the autonomous regions of Tibet to the west and Xinjiang to the northwest. It is under the administration of Yushu Tibetan Autonomous Prefecture.
Zhidoi County is divided to 1 town and 5 townships.
Zhidoi County has a dry-winter subalpine climate (Köppen Dwc) bordering upon an alpine climate (ETH), featuring cool, rainy summers and frigid, dry winters. Diurnal temperature variation is substantial throughout the year: an average morning falls below in every month of the year, and in December and January, mean minima are below .