Illinois County Map
Labeled county boundary map and complete directory of all 102 counties in Illinois (IL, State FIPS 17). View 5-digit FIPS codes, county seats, land area in square miles, and official county government websites below.
Showing all 102 counties in Illinois. Use the search box below to filter by county name, 5-digit FIPS code, or county seat.
Illinois County Statistics & Summary
Total Counties
102
Largest by Land Area
McLean County
Smallest by Land Area
Putnam County
All 102 Counties in Illinois (FIPS, County Seat & Official Website)
| County Name | 5-Digit FIPS | Seat / Administrative Center | Land Area (sq mi) | Coordinates | Official Website |
|---|---|---|---|---|---|
| Adams County | 17001 | Quincy | 855.1 | 39.986°, -91.195° | Official Site |
| Alexander County | 17003 | Cairo | 235.4 | 37.184°, -89.350° | Official Site |
| Bond County | 17005 | Greenville | 380.3 | 38.886°, -89.437° | Official Site |
| Boone County | 17007 | Belvidere | 280.7 | 42.319°, -88.824° | Official Site |
| Brown County | 17009 | Mount Sterling | 305.7 | 39.962°, -90.750° | Official Site |
| Bureau County | 17011 | Princeton | 869.1 | 41.401°, -89.528° | Official Site |
| Calhoun County | 17013 | Hardin | 253.8 | 39.164°, -90.666° | — |
| Carroll County | 17015 | Mount Carroll | 445.4 | 42.071°, -89.924° | Official Site |
| Cass County | 17017 | Virginia | 375.8 | 39.969°, -90.246° | Official Site |
| Champaign County | 17019 | Urbana | 996.1 | 40.139°, -88.197° | Official Site |
| Christian County | 17021 | Taylorville | 709.5 | 39.545°, -89.280° | Official Site |
| Clark County | 17023 | Marshall | 501.4 | 39.332°, -87.792° | Official Site |
| Clay County | 17025 | Louisville | 468.4 | 38.747°, -88.482° | Official Site |
| Clinton County | 17027 | Carlyle | 473.9 | 38.606°, -89.426° | Official Site |
| Coles County | 17029 | Charleston | 508.3 | 39.514°, -88.221° | Official Site |
| Cook County | 17031 | Chicago | 944.9 | 41.895°, -87.645° | Official Site |
| Crawford County | 17033 | Robinson | 443.6 | 39.003°, -87.763° | Official Site |
| Cumberland County | 17035 | Toledo | 345.9 | 39.273°, -88.241° | Official Site |
| De Witt County | 17039 | Clinton | 397.6 | 40.181°, -88.902° | Official Site |
| DeKalb County | 17037 | Sycamore | 631.3 | 41.895°, -88.769° | Official Site |
| Douglas County | 17041 | Tuscola | 416.6 | 39.766°, -88.223° | Official Site |
| DuPage County | 17043 | Wheaton | 327.9 | 41.852°, -88.086° | Official Site |
| Edgar County | 17045 | Paris | 623.3 | 39.679°, -87.747° | Official Site |
| Edwards County | 17047 | Albion | 222.4 | 38.417°, -88.048° | — |
| Effingham County | 17049 | Effingham | 478.8 | 39.048°, -88.593° | Official Site |
| Fayette County | 17051 | Vandalia | 716.5 | 39.001°, -89.018° | Official Site |
| Ford County | 17053 | Paxton | 485.6 | 40.596°, -88.225° | Official Site |
| Franklin County | 17055 | Benton, Illinois | 408.9 | 37.992°, -88.926° | Official Site |
| Fulton County | 17057 | Lewistown | 865.7 | 40.465°, -90.202° | Official Site |
| Gallatin County | 17059 | Shawneetown | 322.9 | 37.769°, -88.228° | Official Site |
| Greene County | 17061 | Carrollton | 543.1 | 39.355°, -90.388° | Official Site |
| Grundy County | 17063 | Morris | 418.1 | 41.292°, -88.401° | Official Site |
| Hamilton County | 17065 | McLeansboro | 434.7 | 38.081°, -88.539° | Official Site |
| Hancock County | 17067 | Carthage | 793.7 | 40.401°, -91.169° | Official Site |
| Hardin County | 17069 | Elizabethtown | 177.4 | 37.518°, -88.266° | Official Site |
| Henderson County | 17071 | Oquawka | 378.8 | 40.815°, -90.941° | Official Site |
| Henry County | 17073 | Cambridge | 823.2 | 41.350°, -90.131° | Official Site |
| Iroquois County | 17075 | Watseka | 1,117.4 | 40.749°, -87.834° | Official Site |
| Jackson County | 17077 | Murphysboro | 583.6 | 37.786°, -89.381° | Official Site |
| Jasper County | 17079 | Newton | 494.6 | 39.005°, -88.151° | Official Site |
| Jefferson County | 17081 | Mount Vernon | 571.2 | 38.302°, -88.924° | Official Site |
| Jersey County | 17083 | Jerseyville | 369.6 | 39.080°, -90.361° | Official Site |
| Jo Daviess County | 17085 | Galena | 600.9 | 42.362°, -90.212° | Official Site |
| Johnson County | 17087 | Vienna | 343.7 | 37.461°, -88.882° | — |
| Kane County | 17089 | Geneva | 519.4 | 41.940°, -88.428° | Official Site |
| Kankakee County | 17091 | Kankakee | 676.5 | 41.139°, -87.861° | Official Site |
| Kendall County | 17093 | Yorkville | 320.2 | 41.588°, -88.431° | — |
| Knox County | 17095 | Galesburg | 716.4 | 40.931°, -90.214° | Official Site |
| Lake County | 17097 | Waukegan | 443.7 | 42.186°, -87.806° | Official Site |
| LaSalle County | 17099 | Ottawa | 1,135.1 | 41.343°, -88.886° | Official Site |
| Lawrence County | 17101 | Lawrenceville | 372.2 | 38.719°, -87.730° | Official Site |
| Lee County | 17103 | Dixon | 724.8 | 41.748°, -89.300° | Official Site |
| Livingston County | 17105 | Pontiac | 1,043.6 | 40.894°, -88.553° | Official Site |
| Logan County | 17107 | Lincoln | 618.1 | 40.129°, -89.365° | Official Site |
| Macon County | 17115 | Decatur | 580.5 | 39.860°, -88.962° | Official Site |
| Macoupin County | 17117 | Carlinville | 863 | 39.266°, -89.926° | Official Site |
| Madison County | 17119 | Edwardsville | 715.5 | 38.827°, -89.900° | Official Site |
| Marion County | 17121 | Salem | 572.5 | 38.648°, -88.920° | Official Site |
| Marshall County | 17123 | Lacon | 386.8 | 41.031°, -89.342° | Official Site |
| Mason County | 17125 | Havana | 539.4 | 40.239°, -89.913° | Official Site |
| Massac County | 17127 | Metropolis | 237.2 | 37.216°, -88.706° | Official Site |
| McDonough County | 17109 | Macomb | 589.3 | 40.456°, -90.679° | Official Site |
| McHenry County | 17111 | Woodstock | 603.4 | 42.324°, -88.452° | Official Site |
| McLean County | 17113 | Bloomington | 1,183.2 | 40.495°, -88.844° | Official Site |
| Menard County | 17129 | Petersburg | 314.4 | 40.023°, -89.794° | Official Site |
| Mercer County | 17131 | Aledo | 561.2 | 41.206°, -90.742° | Official Site |
| Monroe County | 17133 | Waterloo | 385.3 | 38.278°, -90.179° | Official Site |
| Montgomery County | 17135 | Hillsboro | 703.8 | 39.228°, -89.478° | Official Site |
| Morgan County | 17137 | Jacksonville | 569 | 39.718°, -90.205° | Official Site |
| Moultrie County | 17139 | Sullivan | 336 | 39.637°, -88.626° | Official Site |
| Ogle County | 17141 | Oregon | 758.7 | 42.042°, -89.320° | Official Site |
| Peoria County | 17143 | Peoria | 618.7 | 40.786°, -89.767° | Official Site |
| Perry County | 17145 | Pinckneyville | 441.9 | 38.084°, -89.368° | Official Site |
| Piatt County | 17147 | Monticello | 439.2 | 40.009°, -88.592° | Official Site |
| Pike County | 17149 | Pittsfield | 831.4 | 39.625°, -90.889° | Official Site |
| Pope County | 17151 | Golconda | 368.9 | 37.417°, -88.542° | Official Site |
| Pulaski County | 17153 | Mound City | 199.3 | 37.216°, -89.128° | Official Site |
| Putnam County | 17155 | Hennepin | 160.1 | 41.199°, -89.298° | Official Site |
| Randolph County | 17157 | Chester | 575.4 | 38.056°, -89.821° | Official Site |
| Richland County | 17159 | Olney | 360 | 38.712°, -88.085° | — |
| Rock Island County | 17161 | Rock Island | 427.5 | 41.468°, -90.572° | Official Site |
| Saline County | 17165 | Harrisburg | 380 | 37.752°, -88.545° | Official Site |
| Sangamon County | 17167 | Springfield | 868.2 | 39.756°, -89.663° | Official Site |
| Schuyler County | 17169 | Rushville | 437.3 | 40.157°, -90.614° | Official Site |
| Scott County | 17171 | Winchester | 250.8 | 39.637°, -90.478° | Official Site |
| Shelby County | 17173 | Shelbyville | 758.5 | 39.385°, -88.799° | Official Site |
| St. Clair County | 17163 | Belleville | 657.7 | 38.470°, -89.928° | Official Site |
| Stark County | 17175 | Toulon | 288.1 | 41.097°, -89.797° | Official Site |
| Stephenson County | 17177 | Freeport | 564.2 | 42.350°, -89.666° | Official Site |
| Tazewell County | 17179 | Pekin | 646.5 | 40.508°, -89.516° | Official Site |
| Union County | 17181 | Jonesboro | 413.4 | 37.486°, -89.245° | Official Site |
| Vermilion County | 17183 | Danville | 898.3 | 40.187°, -87.727° | Official Site |
| Wabash County | 17185 | Mount Carmel | 223.3 | 38.446°, -87.839° | — |
| Warren County | 17187 | Monmouth | 542.4 | 40.850°, -90.620° | Official Site |
| Washington County | 17189 | Nashville | 562.6 | 38.353°, -89.417° | Official Site |
| Wayne County | 17191 | Fairfield | 713.8 | 38.432°, -88.432° | Official Site |
| White County | 17193 | Carmi | 495 | 38.087°, -88.178° | Official Site |
| Whiteside County | 17195 | Morrison | 684.1 | 41.751°, -89.911° | Official Site |
| Will County | 17197 | Joliet | 835.9 | 41.449°, -87.978° | Official Site |
| Williamson County | 17199 | Marion | 420.2 | 37.730°, -88.930° | Official Site |
| Winnebago County | 17201 | Rockford | 513 | 42.337°, -89.161° | Official Site |
| Woodford County | 17203 | Eureka | 527.6 | 40.790°, -89.211° | Official Site |
How Illinois Counties and 5-Digit FIPS Codes Work
In U.S. Census Bureau TIGER/Line geography, Illinois (IL) is assigned the 2-digit state Federal Information Processing Series (FIPS) code 17 and covers 55,514 square miles of land area across 102 counties in the Central Time (CT) zone (with Springfield as the state capital). Every county in the directory above carries a unique 5-digit GEOID formed by combining state prefix 17 with a 3-digit county code (ranging alphabetically from Adams County at 17001 to Woodford County at 17203).
Because U.S. Postal Service 5-digit ZIP Codes follow mail carrier delivery routes rather than local government borders, many postal addresses in Illinois carry a neighboring city’s mailing name or sit inside a multi-county ZIP Code Tabulation Area (ZCTA). Property tax assessments, deed recording, circuit and county court venue, voter registration precincts, sheriff jurisdiction, and county sales tax rates in Illinois are determined by the legal county boundary shown on the map above rather than the postal city name on an envelope.
Land area figures in square miles and internal centroid coordinates (INTPTLAT, INTPTLON) come directly from the U.S. Census Bureau’s current TIGERweb State_County benchmark, while 102 administrative seats and 96 verified official government websites are cross-referenced from Wikidata (CC0). Need a clean outline worksheet without county labels, or want to verify which Illinois county a specific home or business address sits in? Open the Blank Map of Illinois, run a street-segment check on Address to County Lookup, check multi-county postal overlap on ZIP Code to County Lookup, or browse all 50 states on the National U.S. County Map.
Adjacent State County Maps
Explore county maps and FIPS directories for states bordering Illinois: