Seydun County () is in Khuzestan province, Iran. Its capital is the city of Seydun, whose population at the time of the 2016 National Census was 7,650 people in 1,803 households.
In 2022, Seydun District was separated from Bagh-e Malek County in the establishment of Seydun County, which was divided into two districts of two rural districts each, with Seydun as its capital and only city.
Seydun County's administrative structure is shown in the following table.