Illinois Route 101 (IL 101) is a 19.43-mile-long (31.27 km)[1] east–west state road that runs from to the intersection of Illinois Route 61 in Augusta east to U.S. Highway 67 one mile (1.6 km) east of Littleton.

The highway was officially established in 1924 along its current alignment.

Route 101 is maintained by the Illinois Department of Transportation.

[3] The route leaves Augusta to the east and crosses into Schuyler County, entering Weinberg-King State Park across the county line.

The highway continues east past the park until the community of Brooklyn, where it meets Route 99.