Mehdishahr County (Persian: شهرستان مهدی‌شهر) is in Semnan province, Iran.

[3] At the time of the 2011 census, the county's population was 41,896 people in 11,997 households.

[4] The 2016 census measured the population of the county as 47,475 in 15,226 households.

[2] Mehdishahr County's population history and administrative structure over two consecutive censuses are shown in the following table.

Media related to Mahdishahr County at Wikimedia Commons Iran portal This Semnan province location article is a stub.