Shamkan District () is in Sheshtamad County, Razavi Khorasan province, Iran. It is administered from the city of Shamkan, whose population at the time of the 2016 National Census was 1,882 in 581 households.
In 2020, Sheshtamad District was separated from Sabzevar County in the establishment of Sheshtamad County, which was divided into two districts of two rural districts each, with the city of Sheshtomad as its capital. The village of Shamkan was converted to a city in 2022.