Jerseyville is a city located in Jersey County Illinois. It is also the county seat of Jersey County. With a 2020 population of 8,178, it is the 251st largest city in Illinois and the 3565th largest city in the United States . Jerseyville is currently declining at a rate of -0.13% annually and its population has decreased by -3.39% since the most recent census, which recorded a population of 8,465 in 2010. Jerseyville reached it's highest population of 8,522 in 2013. Spanning over 5 miles, Jerseyville has a population density of 1,566 people per square mile.
The average household income in Jerseyville is $65,964 with a poverty rate of 11.29%. The median rental costs in recent years comes to $626 per month, and the median house value is $114,000. The median age in Jerseyville is 39.2 years, 38.2 years for males, and 41.5 years for females.