It runs from Illinois Route 37 north of Grand Chain east to U.S. Route 45 east of Boaz.

This is a distance of 9.04 miles (14.55 km).

It is also the southernmost east–west state route in Illinois.

Illinois 169 is a two-lane surface road for its entire length.

SBI Route 169 originally ran from Shelbyville to Dalton City on what is now Illinois Route 128.