Lewistown is a city and the county seat of Fulton County, Illinois, United States. It was named by its founder, Ossian M. Ross, after his oldest son, Lewis W. Ross. The population was 2,041 at the 2020 census. Located in central Illinois, it is southwest of Peoria. It is the source of Spoon River Anthology by Edgar Lee Masters, who lived there. Native American burial mounds are nearby at Dickson Mounds off Illinois Route 97.

Fulton County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 33,609. Its county seat is Lewistown, and the largest city is Canton. Fulton County comprises the Canton, IL Micropolitan Statistical Area, which is part of the Peoria-Canton, IL Combined Statistical Area.