Irwin County is a county located in the U.S. state of Georgia. As of the 2020 census, the population was 9,666. The county seat is Ocilla. The county was created on December 15, 1818. It was named for Governor Jared Irwin. In the last years of the American Civil War, Irwin County gained the nickname of the Republic of Irwin due to the Unionism of many of its residents. The location where Jefferson Davis was captured is located in Irwin County near Irwinville.