Chicagoland Linux Users Group: Gathering in the Chicago area. Includes meeting times, install fest information and a mailing list.
DePaul Linux Users' Group: LUG of the DePaul University. Site contains a mailing list, a web forum and meetings information.
Linux Users of Central Illinois: The Linux Users Group of Springfield, Illinois and the surrounding area.
NWCLUG: Northwest Chicagoland Linux User Group.
Rock River Linux Users Group ( RRLug): A Linux Users Group based in Rockford, Illinois. The site contains events and presentations, a library, book reviews, and screenshots.
SLUUG- St. Louis Unix Users Group: Vendor-independent organization dedicated to promoting Open Systems and the Linux and UNIX operating systems.
Southern Illinois Linux Users Group: Linux users group of Carbondale (Southern Illinois University) and the surrounding area.