Qaen County () is in South Khorasan province, Iran. Its capital is the city of Qaen. This city is known as âÂÂThe Capital of SaffronâÂÂ.
After the 2011 National Census, Zirkuh and Zohan Districts were separated from the county in the establishment of Zirkuh County.
At the time of the 2006 census, the county's population was 137,357 in 35,783 households. The following census in 2011 counted 152,401 people in 42,002 households. The 2016 census measured the population of the county as 116,181 in 34,794 households.
Qaen County's population history and administrative structure over three consecutive censuses are shown in the following table.