Illinois is a thriving state with so much to offer! Below is an interactive map of the state added with a complete list of counties. Illinois has an estimated population of more than 12,800,000, more than 5,350,000 housing units and an average median household income of $61,229.
State slogan: Land of Lincoln
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Map of Illinois
Counties in Illinois
County | Seat | Est. | Population |
Cook County | Chicago | 1831 | 5,194,675 |
DuPage County | Wheaton | 1839 | 916,924 |
Lake County | Waukegan | 1839 | 703,462 |
Will County | Joliet | 1836 | 677,560 |
Kane County | Geneva | 1836 | 515,269 |
McHenry County | Woodstock | 1836 | 308,760 |
Winnebago County | Rockford | 1836 | 295,266 |
St. Clair County | Belleville | 1790 | 270,056 |
Madison County | Edwardsville | 1812 | 269,282 |
Champaign County | Urbana | 1833 | 201,081 |
Sangamon County | Springfield | 1821 | 197,465 |
Peoria County | Peoria | 1825 | 186,494 |
McLean County | Bloomington | 1830 | 169,572 |
Rock Island County | Rock Island | 1831 | 147,546 |
Tazewell County | Pekin | 1827 | 135,394 |
Kendall County | Yorkville | 1841 | 114,736 |
LaSalle County | Ottawa | 1831 | 113,924 |
Kankakee County | Kankakee | 1853 | 113,449 |
Macon County | Decatur | 1829 | 110,768 |
DeKalb County | Sycamore | 1837 | 105,160 |
Vermilion County | Danville | 1826 | 81,625 |
Adams County | Quincy | 1825 | 67,103 |
Williamson County | Marion | 1839 | 66,357 |
Jackson County | Murphysboro | 1816 | 60,218 |
Whiteside County | Morrison | 1836 | 58,498 |
Boone County | Belvidere | 1837 | 54,165 |
Coles County | Charleston | 1830 | 53,873 |
Ogle County | Oregon | 1836 | 53,497 |
Knox County | Galesburg | 1825 | 52,919 |
Henry County | Cambridge | 1825 | 50,486 |
Grundy County | Morris | 1841 | 50,063 |
Macoupin County | Carlinville | 1829 | 47,765 |
Stephenson County | Freeport | 1837 | 47,711 |
Franklin County | Benton | 1818 | 39,561 |
Marion County | Salem | 1823 | 39,437 |
Livingston County | Pontiac | 1837 | 38,950 |
Jefferson County | Mount Vernon | 1819 | 38,827 |
Woodford County | Eureka | 1841 | 38,664 |
Clinton County | Carlyle | 1824 | 37,762 |
Fulton County | Lewistown | 1823 | 37,069 |
Lee County | Dixon | 1839 | 36,031 |
Morgan County | Jacksonville | 1823 | 35,547 |
Bureau County | Princeton | 1837 | 34,978 |
Christian County | Taylorville | 1839 | 34,800 |
Effingham County | Effingham | 1831 | 34,242 |
Randolph County | Chester | 1795 | 33,476 |
Monroe County | Waterloo | 1816 | 32,957 |
McDonough County | Macomb | 1826 | 32,612 |
Logan County | Lincoln | 1839 | 30,305 |
Montgomery County | Hillsboro | 1821 | 30,104 |
Iroquois County | Watseka | 1833 | 29,718 |
Saline County | Harrisburg | 1847 | 24,913 |
Jersey County | Jerseyville | 1839 | 22,985 |
Jo Daviess County | Galena | 1827 | 22,678 |
Shelby County | Shelbyville | 1827 | 22,363 |
Perry County | Pinckneyville | 1827 | 22,350 |
Fayette County | Vandalia | 1821 | 22,140 |
Douglas County | Tuscola | 1859 | 19,980 |
Crawford County | Robinson | 1816 | 19,817 |
Hancock County | Carthage | 1825 | 19,104 |
Edgar County | Paris | 1823 | 18,576 |
Union County | Jonesboro | 1818 | 17,808 |
Bond County | Greenville | 1817 | 17,768 |
Warren County | Monmouth | 1825 | 17,707 |
Lawrence County | Lawrenceville | 1821 | 16,833 |
Wayne County | Fairfield | 1819 | 16,760 |
Piatt County | Monticello | 1841 | 16,729 |
DeWitt County | Clinton | 1839 | 16,561 |
Mercer County | Aledo | 1825 | 16,434 |
Pike County | Pittsfield | 1821 | 16,430 |
Clark County | Marshall | 1819 | 16,335 |
Richland County | Olney | 1841 | 16,233 |
Massac County | Metropolis | 1843 | 15,429 |
Carroll County | Mount Carroll | 1839 | 15,387 |
Moultrie County | Sullivan | 1843 | 14,846 |
Washington County | Nashville | 1818 | 14,716 |
Mason County | Havana | 1841 | 14,666 |
White County | Carmi | 1815 | 14,665 |
Ford County | Paxton | 1859 | 14,081 |
Greene County | Carrollton | 1821 | 13,886 |
Clay County | Louisville | 1824 | 13,815 |
Cass County | Virginia | 1837 | 13,642 |
Menard County | Petersburg | 1839 | 12,705 |
Marshall County | Lacon | 1839 | 12,640 |
Johnson County | Vienna | 1812 | 12,582 |
Wabash County | Mount Carmel | 1824 | 11,947 |
Cumberland County | Toledo | 1843 | 11,048 |
Jasper County | Newton | 1831 | 9,698 |
Hamilton County | McLeansboro | 1821 | 8,457 |
Alexander County | Cairo | 1819 | 8,238 |
Schuyler County | Rushville | 1825 | 7,544 |
Henderson County | Oquawka | 1841 | 7,331 |
Brown County | Mount Sterling | 1839 | 6,937 |
Edwards County | Albion | 1814 | 6,721 |
Pulaski County | Mound City | 1843 | 6,161 |
Putnam County | Hennepin | 1825 | 6,006 |
Stark County | Toulon | 1839 | 5,994 |
Gallatin County | Shawneetown | 1812 | 5,589 |
Scott County | Winchester | 1839 | 5,355 |
Calhoun County | Hardin | 1825 | 5,089 |
Pope County | Golconda | 1816 | 4,470 |
Hardin County | Elizabethtown | 1839 | 4,320 |