Greenville is a city in Bond County, Illinois, United States, 51 miles east of St. Louis. The population as of the 2020 census was 7,083, up from 7,000 at the 2010 census. It is the county seat of Bond County. Greenville is part of the St. Louis Metropolitan Statistical Area. It is also considered part of the Metro East region of Illinois. Greenville celebrated its Bicentennial in 2015 as one of the oldest communities in Illinois.