Eyvan County () is in Ilam province, Iran. Its capital is the city of Eyvan.
The population of Eyvan County is mainly Kurdish.
At the time of the 2006 National Census, the county's population was 47,380 in 10,040 households. The following census in 2011 counted 48,833 people in 11,859 households. The 2016 census measured the population of the county as 49,491 in 13,820 households.
Eyvan County's population history and administrative structure over three consecutive censuses are shown in the following table.
List of cities and villages in the county by historical population (ranked according to the 2016 National Census)