Chillicothe is a city on the Illinois River in Peoria County, Illinois, United States. The population was 6,097 at the 2010 census. Chillicothe is just north of the city of Peoria and is part of the Peoria Metropolitan Statistical Area.
Chillicothe is located at 40°55′11″N 89°29′34″W.
According to the 2010 census, Chillicothe has a total area of 5.415 square miles (14.02 km2), of which 5.13 square miles (13.29 km2) (or 94.74%) is land and 0.285 square miles (0.74 km2) (or 5.26%) is water.
Chillicothe is located on the Illinois River and on the parallel Iowa Interstate Railroad (IAIS) branch, from Bureau to Peoria, which was formerly the Rock Island Railroad. Crossing the IAIS and the Illinois River at Chillicothe is the former Santa Fe Railroad, now owned by BNSF Railway. Almost 4 miles outside of town the BNSF Railway operates one of the most notable civil engineering points on the Chillicothe Subdivision. Edelstein Hill is one of the steepest climbs on the railway system and attracts many railfans to see locomotives pulling intermodal trains up the hill.
The Illinois River runs both north and south connecting Chicago with St. Louis. Barge traffic is occasional as it is an efficient means of transportation for some bulk products.