Sarmin is a town situated in northwestern Syria within the Idlib Governorate. It is positioned at an altitude of approximately 390 meters and lies roughly 15 kilometers southeast of the city of Idlib.
The town is surrounded by several nearby localities, including Binnish to the north, Talhiyah to the northeast, Afs to the east, Saraqib to the southeast, al-Nayrab to the south, and Qminas to the southwest. The Taftanaz Military Airbase is located about 9 kilometers to the northeast of Sarmin.