Sakht Sar Rural District () is in the Central District of Ramsar County, Mazandaran province, Iran. It is administered from the city of Ramsar.
At the time of the 2006 National Census, the rural district's population was 6,305 in 1,795 households. There were 6,169 inhabitants in 1,950 households at the following census of 2011. The 2016 census measured the population of the rural district as 6,462 in 2,174 households. The most populous of its 95 villages was Talesh Mahalleh-ye Fatuk, with 1,106 people.