An illustrated map of Illinois legislative districts can be found on the Illinois Secretary of State website here.
District 1: City of Chicago
District 2: Suburban Cook County
District 3: North Eastern Illinois
Composed of the following counties:
DuPage Kendall Kane
Lake Grundy Will
McHenry Kankakee
District 4: Includes the following Areas:
Area 4: North Western Illinois
Composed of the following counties:
Whiteside Winnebago DeKalb
Stephenson Boone Ogle
Jo Davies Carroll Lee
Area 5: Western Illinois
Composed of the following counties:
Rock Island McDonough Knox
Mercer Fulton Peoria
Woodford Stark Henry
Putnam Tazewell Bureau
LaSalle Marshall Warren
Henderson Hancock
Area 6: West Central Illinois
Composed of the following counties:
Adams Menard Greene
Schuyler Sangamon Mason
Macoupin Pike Logan
Montgomery Scott Brown
Morgan Christian Jersey
Cass Calhoun
Area 7: East Central Illinois
Composed of the following counties:
Livingston Champaign Shelby
Iroquois Vermilion Coles
Cumberland McLean Macon
Ford Moultrie Clark
DeWitt Douglas Piatt
Edgar
Area 8: Southern Illinois
Composed of the following counties:
Madison Richland Bond
Franklin Lawrence Hardinx
Hamilton Alexander White
Fayette Pulaski Monroe
Effingham Washington Massac
Jackson Jasper Wayne
Jefferson Williamson Saline
Crawford St. Clair Edwards
Gallton Clinton Union
Wabash Randolph Clay
Marion Johnson Perry
Pope