Jerseyville is a city in Jersey County, Illinois, United States. The population was 7,984 at the 2000 census, and the population was 8,373 in the 2008 official US Census estimate. It is the county seat of Jersey County, and is also the largest city in the county. The city's current mayor is Yvonne Hartmann. Jerseyville is a part of Southern Illinois, the Metro-East region, and the St. Louis Metropolitan Statistical Area.