Jajrom County () is in North Khorasan province, Iran. Its capital is the city of Jajrom.
In 2008, Golestan Rural District, the city of Daraq, parts of Miyan Dasht Rural District, and parts of the city of Jajrom were separated from the Central District in the establishment of Garmeh County.
At the time of the 2006 National Census, the county's population was 57,349, in 14,803 households. The following census in 2011 counted 36,898 people in 10,532 households. The 2016 census measured the population of the county as 36,673 in 11,154 households.
Jajrom County's population history and administrative structure over three consecutive censuses are shown in the following table.