The Central District of Seydun County () is in Khuzestan province, Iran. Its capital is the city of Seydun.
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.
At the time of the 2006 National Census, the district's population (as Seydun District of Bagh-e Malek County) was 22,412 in 4,012 households. The following census in 2011 counted 22,965 people in 4,883 households. The 2016 census measured the population of the district as 22,246 inhabitants in 5,197 households.