Illinois Route 68 is an east–west state highway in northeast Illinois. It runs east from Illinois Route 72 (Higgins Road) in the Dundee area to the Interstate 94/U.S. Route 41 concurrency (Edens Expressway) in Glencoe. This is a distance of 25.74 miles (41.42 km).

Illinois 68 is called Dundee Road east of Route 25. It is known as Penny Avenue in East Dundee. East in Glencoe it continues as a local road to Green Bay Road.

The Dundee area refers to the cities of East Dundee and West Dundee. The towns are named after Dundee, Scotland, the hometown of a young settler who won the naming rights in a competition.

SBI Route 68 originally ran from Lake Bluff to the Wisconsin state line on what is now Illinois Route 131 and U.S. Route 41. Route 68 was changed to these routes from 1935 through 1937. In 1942, it was moved to the current Illinois 68 between Illinois Route 59 and then Illinois Route 42, which is still Sheridan Road to this day. In 1972, Illinois 68 was dropped east of U.S. 41, which today is also Interstate 94. The next year, it was extended west to East Dundee, replacing Illinois Route 63 and Illinois Route 22A.