Gomishan County () is in Golestan Province, Iran. Its capital is the city of Gomish Tappeh.
In 2009, Gomishan District was separated from Torkaman County in the establishment of Gomishan County, which was divided into two districts of two rural districts each, with Gomish Tappeh as its capital.
At the time of the 2011 National Census, the county's population was 63,447 people in 14,645 households. The 2016 census measured the population of the county as 68,773 in 18,474 households.
Gomishan County's population history and administrative structure over two consecutive censuses are shown in the following table.