| Official Name: | Shahmirzad |
| Native Name: | fa|شهميرزاد |
| Settlement Type: | City |
| Pushpin Map: | Iran |
| Subdivision Type: | Country |
| Subdivision Name: | Iran |
| Subdivision Type1: | Province |
| Subdivision Name1: | Semnan |
| Subdivision Type2: | County |
| Subdivision Name2: | Mehdishahr |
| Subdivision Type3: | District |
| Subdivision Name3: | Shahmirzad |
| Population As Of: | 2016 |
| Population Total: | 11191 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Coordinates: | 35.7692°N 53.3361°W |
| Coordinates Footnotes: | [1] |
Shahmirzad (fa|شهميرزاد) is a city in, and the capital of, Shahmirzad District of Mehdishahr County, Semnan province, Iran.[2] It is in the northern part of the country and on the southern slopes of the Alborz Mountains.
The Shahmirzadi language (شامرزایی) is a Caspian language close to Mazandarani.[3]
At the time of the 2006 National Census, the city's population was 7,273 in 1,860 households, when it was in the former Mehdishahr District of Semnan County.[4] The following census in 2011 counted 8,882 people in 2,625 households,[5] by which time the district had been separated from the county in the establishment of Mehdishahr County. Shahmirzad was transferred to the new Shahmirzad District.[2] The 2016 census measured the population of the city as 11,191 people in 3,789 households.[6] During the summer, the city's population approaches 40,000 as tourists come for its cool climate and popular gardens.
Shahmirzad has been home to people of diverse ethnic backgrounds, a large group of whom seasonally settled in cities and towns of Mazandaran, such as Babol, Sari, Neka, and Behshahr. During the past decades many Muslim, Bahá'í, and Shahmirzadi Jews,[7] migrated to larger cities in Iran and abroad, most notably San Francisco Bay Area.
Shahmirzad's walnut orchard with a size of is noted by the UN, Food and Agriculture Organization, as the largest of its kind in the world.[8] Shahmirzadi homeowners are given a proprietary interest in the walnut orchard in proportion to the amount of land they own in the village. Shahmirzad also produces mineral water "Tenab Shahmirzad".[9] [10]