Amirabad District () is in Damghan County, Semnan province, Iran. Its capital is the city of Amiriyeh.
At the time of the 2006 National Census, the district's population was 9,026 in 2,717 households. The following census in 2011 counted 10,413 people in 3,150 households. The 2016 census measured the population of the district as 12,296 inhabitants in 4,122 households.