Illinois Route 71 is a 66-mile (106 km) long southwest-to-northeast state highway in north central Illinois. It runs from the end of Interstate 180 in Hennepin to U.S. Route 34 in Oswego. This is a distance of 69.37 miles (111.64 km).

Outside of Hennepin, the road stretches east to an intersection with Interstate 39 near Oglesby, paralleling I-39 to the north for several miles on a concurrency with Illinois Route 351 before turning eastward again near LaSalle-Peru.

Between LaSalle-Peru and Ottawa, Route 71 parallels the south bank of the Illinois River and passes Starved Rock State Park. It then crosses the Illinois River on a simple four-lane girder bridge. It overlaps Illinois Route 23 through downtown Ottawa and U.S. Route 6 east from Route 23 before intersecting with Interstate 80. From here it continues to the northeast, passing through Norway, Newark, and Yorkville. Its eastern terminus is near downtown Oswego at an intersection with U.S. Highway 34 and Wolfs Crossing Road.

The proposed Prairie Parkway limited-access highway will interchange with Route 71 southwest of High Point Road near Yorkville.

Just south of Norway, there is a memorial dedicated to Norwegian immigrants who settled in the area, with a small park, a cemetery, and a plaque from King Olav V. This memorial commemorates the Fox River Settlement. Dating from 1834, this was the location of the first permanent Norwegian-American immigrant settlement in the Midwest.

Near E. 26th Road, south of Norway, Illinois, there is also a crashed airplane which serves as a "memorial" of sorts to commemorate the 1980s agricultural crash, which affected the primarily rural farming county.