Illinois Route 56 is an east–west state road in northern and northeastern Illinois. It runs from the interchange of Illinois Route 47 at U.S. Route 30 in Sugar Grove east to US 12/US 20/US 45 (Mannheim Road) by Bellwood. This is a distance of 32.52 miles (52.34 km).

Illinois 56 parallels Interstate 88 (Ronald Reagan Memorial Tollway) for its entire length and merges with it at Illinois Route 31, making it the only state road to be marked as a toll road. Only Illinois Route 190 and Illinois Route 5 have ever had this distinction. Traveling westbound; after crossing the Fox River, Illinois 56 travels south along Illinois Route 31 until it joins I-88. Illinois 56 runs with the I-88 tollway until it exits the tollway just west of Orchard Road and terminates in Sugar Grove. (That section is a Freeway).

Route 56 is called Butterfield Road for its entire length east of Illinois Route 25 until it meets its end as Washington Boulevard in Bellwood. It serves the major cities of Aurora, Wheaton, Downers Grove and Oak Brook, as well as the College of DuPage and the Oakbrook Center, and runs within the Illinois Technology and Research Corridor. It also forms the southern border of Fermilab in Batavia.

SBI Route 56 was the current Illinois 56 from Oak Brook to Bellwood on Butterfield Road. In 1965 it was extended west to Sugar Grove over Illinois Route 55. In 1972, the eastern end was truncated to its current location. The western end of Illinois 56 is part of the old alignment of the old east–west Tollway.

or westbound 38 from westbound 56

Eastbound - Only IL 83 northbound is accessible

East end of concurrency with I-88