Kalat County (Persian: شهرستان کلات) is in Razavi Khorasan province, Iran. Its capital is the city of Kalat.

After the 2016 National Census, Charam Rural District was created in the Central District, and Hezarmasjed Rural District was separated from it in the formation of Hezarmasjed District, including the new Layen Rural District. In addition, the villages of Chenar and Hasanabad-e Layen-e Now were elevated to city status.

Around half of the people of Kalat County are Turkic peoples of Azeri origin, ,Tekke Turkmen; 35% are Kurdish and 15% are Persian.

At the time of the 2006 census, the county's population was 39,560 in 9,489 households. The following census in 2011 counted 38,232 people in 10,298 households. The 2016 census measured the population of the county as 36,237, in 10,708 households.

Kalat County's population history and administrative structure over three consecutive censuses are shown in the following table.

Media related to Kalat County at Wikimedia Commons