Arjestan Rural District (Persian: دهستان ارجستان) is in Sabalan District of Sareyn County, Ardabil province, Iran. Its capital is the village of Atashgah.

After the 2006 National Census, Sareyn District was separated from Ardabil County in the establishment of Sareyn County, which was divided into two districts of two rural districts each, with Sareyn as its capital and only city.

There were 3,269 inhabitants in 941 households at the following census of 2011. At the most recent census of 2016, the population of the rural district was 3,097 in 899 households. The most populous of its eight villages was Sain, with 947 people.