Qaen County (Persian: شهرستان قائن)[a] is in South Khorasan province, Iran.

[4] At the time of the 2006 census, the county's population was 137,357 in 35,783 households.

[6] The 2016 census measured the population of the county as 116,181 in 34,794 households.

[2] Qaen County's population history and administrative structure over three consecutive censuses are shown in the following table.

Media related to Qaen County at Wikimedia Commons