Fayetteville, officially the Village of Fayetteville is a village on the Kaskaskia River. Because of that, the village is nicknamed the Gateway to the Kaskaskia. Fayetteville is named after Marquis de Lafayette, a french general who fought for the US in the revolutionary war. Fayetteville is in Fayettville Township, St. Clair County, Illinois, United States. As of the 2020 census, Fayetteville had a population of 302. And as of the 2026 estimate, Fayetteville has a population of 282.