Khoshab County () is in Razavi Khorasan province, Iran. Its capital is the city of Soltanabad.
In 2010, Khoshab District was separated from Sabzevar County in the establishment of Khoshab County, which was divided into two districts of two rural districts each, with Soltanabad as its capital and only city at the time.
In 2019, Tabas Rural District was separated from the Central District in the formation of Now Deh-e Anqolab District, including the new Now Deh-e Anqolab Rural District. The village of Meshkan was converted to a city in 2017, and likewise the village of Now Deh-e Anqolab in 2020.
At the time of the 2011 National Census, the county's population was 37,914 people in 10,989 households. The 2016 census measured the population of the county as 37,181 in 11,883 households.
Khoshab County's population history and administrative structure over two consecutive censuses are shown in the following table.