Kashmar County is in Razavi Khorasan province of Iran. Its capital is the city of Kashmar.
In 2019, Farah Dasht District was formed and divided into the new Qaleh-ye Bala and Rezqabad Rural Districts. At the same time, Kuhsorkh District was separated from the county in the establishment of Kuhsorkh County. Two villages were merged to form the new village of Farg Qaleh in 2021, which was converted to a city in 2022.
At the time of the 2006 National Census, the county's population was 146,536 in 39,554 households. The following census in 2011 counted 157,149 people in 46,726 households. The 2016 census measured the population of the county as 168,664 in 52,778 households.
Kashmar County's population history and administrative structure over three consecutive censuses are shown in the following table.