Harrisburg is a city located in the state of Illinois within the United States. It serves as the county seat for Saline County and functions as the principal city within the Harrisburg micropolitan statistical area.
The city is situated approximately 55 miles southwest of Evansville, Indiana, and 111 miles southeast of St. Louis, Missouri. It is positioned within the Illinois–Indiana–Kentucky tri-state area. As of the 2020 census, the city had a population of 8,219, while the surrounding Harrisburg Township had a total population of 10,037.