Garmsar (Persian: گرمسار) is a city in the Central District of Garmsar County, Semnan province, Iran, serving as capital of both the county and the district.
Garmsar is about 95 kilometres (59 mi) southeast of Tehran. It lies on the edge of Dasht-e Kavir, Irans largest desert. Many people in the city commute to Tehran due to its proximity. Ghasre Bahram, The Stone Way, Stonvand Castle, the Sar Darre Mountains, and Kavir Desert National Park are tourist attractions located in the area.