Du Quoin is a city in Perry County, Illinois, United States. Its name reflects an alternate spelling of the surname of Jean Baptiste de Coigne, a chief of the Tamaroa and later Kaskaskia indigenous people of the area during the American Revolutionary War and early statehood. As of the 2020 census, Du Quoin had a population of 5,827. It is best known for hosting the annual DuQuoin State Fair and the Street Machine Nationals.