Toulon is a city in Stark County, Illinois, United States. The population was 1,400 at the 2000 census. It is the county seat of Stark County. Toulon is part of the Peoria, Illinois Metropolitan Statistical Area, and is the northwestern terminus of the Rock Island Trail State Park.
Toulon is located at 41°5′40″N 89°51′44″W / 41.09444°N 89.86222°W / 41.09444; -89.86222 (41.094495, -89.862218).
According to the United States Census Bureau, the city has a total area of 0.9 square miles (2.3 km²), all of it land.