Salmanshahr District () is in Abbasabad County, Mazandaran province, Iran. Its capital is the city of Salman Shahr.
In 2009, Abbasabad District was separated from Tonekabon County in the establishment of Abbasabad County, which was divided into two districts of two rural districts each, with the city of Abbasabad as its capital.
In 2012, Kelarabad-e Sharqi Rural District and the city of Kelarabad were separated from Kelarabad District in the formation of Kelar District, with the former renamed Salmanshahr District.
At the time of the 2011 National Census, the district's population was 24,645 people in 7,532 households. The 2016 census measured the population of the district as 16,427 inhabitants in 5,253 households.