Shahrud (Persian: شاهرود‎, also Romanized as Shāhrūd, Shahrood, Shahroud, and Shārūd; formerly, Emamshahr (Persian: اِمامشَهر‎, also Romanized as Emāmshahr) is a city in and capital of Shahrud County, Semnan Province, Iran. At the 2006 census, its population was 126,916, in 35,548 families.

Situated about an altitude of 4413 ft (1345 m), it is located at latitude 36°25'N, longitude 055°01'E. Now, it is the largest city of Semnan Province and also its county has same position in the province. The main launch site of the Iranian Space Agency is near Shahrud.

Some 410 kilometers to the east of Tehran, half-way between the capital and Mashad, and at the junction with the Gorgan road, sits the modern city of Shahrud, which has grown to absorb the historic town of Bastam situated in the hills a few kilometers to the north.

From the north, it is surrounded by the Alborz mountains, and from the south by the arid salty deserts. The river of Tash, after crossing this town, reaches the south deserts. The weather on the mountainous areas is cold and it is somewhat temperate in other parts of the city.