Gomishan (Persian: گميشان) is a city in the Central District of Gomishan County, Golestan province, Iran, serving as capital of both the county and the district. The city's Turkmen name, Kümüş Depe, means "Silver Hill."

At the 2006 National Census, its population was 15,639 in 3,236 households, when it was in the former Gomishan District of Torkaman County. The following census in 2011 counted 17,648 people in 4,078 households, by which time the district had been separated from the county in the establishment of Gomishan County, with Gomishan as its capital. The latest census in 2016 showed a population of 19,191 people in 5,129 households.