Quchan (Ghoochan) is a city in and capital of Quchan County, in Razavi Khorasan Province, Iran. It is located due south of the border city of Ashgabat.
Quchan is in the north-east of Iran in Razavi Khorasan Province at an elevation of 1,149 meters above sea level north of the Shah Jahan Mountains. It is located south of the border with Turkmenistan. Quchan is connected by road to Mashhad, 125 km southeast and Turkmenistan, 100 km north.
On 20 June 1747, Nader Shah was assassinated in Quchan.