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Midwest county atlas

Illinois county map

Explore all 102 counties. Select a county to see its map, or download a copy for your next project.

2025 Census boundaries102 mapped unitsCapital: Springfield
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Boundary map 100%
Labelled map of Illinois counties Adams CountyAlexander CountyBond CountyBoone CountyBrown CountyBureau CountyCalhoun CountyCarroll CountyCass CountyChampaign CountyChristian CountyClark CountyClay CountyClinton CountyColes CountyCook CountyCrawford CountyCumberland CountyDe Witt CountyDeKalb CountyDouglas CountyDuPage CountyEdgar CountyEdwards CountyEffingham CountyFayette CountyFord CountyFranklin CountyFulton CountyGallatin CountyGreene CountyGrundy CountyHamilton CountyHancock CountyHardin CountyHenderson CountyHenry CountyIroquois CountyJackson CountyJasper CountyJefferson CountyJersey CountyJo Daviess CountyJohnson CountyKane CountyKankakee CountyKendall CountyKnox CountyLake CountyLaSalle CountyLawrence CountyLee CountyLivingston CountyLogan CountyMacon CountyMacoupin CountyMadison CountyMarion CountyMarshall CountyMason CountyMassac CountyMcDonough CountyMcHenry CountyMcLean CountyMenard CountyMercer CountyMonroe CountyMontgomery CountyMorgan CountyMoultrie CountyOgle CountyPeoria CountyPerry CountyPiatt CountyPike CountyPope CountyPulaski CountyPutnam CountyRandolph CountyRichland CountyRock Island CountySaline CountySangamon CountySchuyler CountyScott CountyShelby CountySt. Clair CountyStark CountyStephenson CountyTazewell CountyUnion CountyVermilion CountyWabash CountyWarren CountyWashington CountyWayne CountyWhite CountyWhiteside CountyWill CountyWilliamson CountyWinnebago CountyWoodford County
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2025 U.S. Census boundaries. Zoom to reveal more names. Drag to pan when zoomed; use arrow keys, + and − with the map focused.

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SVG

SVG is editable vector artwork. PNG is a high-resolution image. PDF uses landscape Letter pages, with a separate key when needed.

Downloads contain the complete boundary map, independent of zoom. Crowded names use a numbered key. Numbered quiz maps use the county list / answer key (CSV). Boundary data (GeoJSON) · Reuse with source credit.

Roads, terrain & aerial imagery

Explore Illinois with a county boundary overlay. Choose a view to load the interactive map.

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Street names, terrain, or aerial photography with the county boundary in view.

Backgrounds load from OpenStreetMap or USGS only when selected. Imagery dates and detail vary by location.

Map scope: Use the boundary map for names and shapes, or the interactive background viewer for roads, terrain, and aerial imagery. County boundaries do not identify parcels or ZIP codes.

Illinois county geography overview

Illinois has 102 counties, which places it 7th among the 50 state and District of Columbia maps in this atlas when ordered by number of county-level units. Their combined 55,513.3 square miles of land place the state 24th by mapped land area.

The average county-level area is 544 square miles, while the median is 511 square miles. The median is often the better description of a typical unit because one or two very large areas can pull the average upward. The five largest units together account for about 10% of the state’s mapped land area.

102county-level units
511 sq mimedian land area
1,183.2 sq milargest unit
4%share of mapped area that is water

Largest and smallest Illinois counties

McLean County is the largest county-level unit by land area at 1,183.2 square miles. It represents about 2% of all mapped land in Illinois. At the other end of the range, Putnam County has 160.1 square miles of land.

Largest by land area

  1. McLean County1,183.2 sq mi
  2. LaSalle County1,135.1 sq mi
  3. Iroquois County1,117.4 sq mi
  4. Livingston County1,043.6 sq mi
  5. Champaign County996.1 sq mi

Smallest by land area

  1. Putnam County160.1 sq mi
  2. Hardin County177.4 sq mi
  3. Pulaski County199.3 sq mi
  4. Edwards County222.4 sq mi
  5. Wabash County223.3 sq mi

Rankings use land area rather than total area. This avoids making coastal or lake counties appear larger solely because their boundaries include extensive water.

Alphabetical list of Illinois counties

The table is alphabetical, so it works as a name and FIPS-code reference rather than an area ranking. Every identifier begins with the Illinois state FIPS prefix 17. Land and water figures are rounded to one decimal place.

102 county-level areas

Download county data / numbered map key (CSV)
No.NameFIPS codeLand areaWater area
1Adams County17001855.1 sq mi16.1 sq mi
2Alexander County17003235.4 sq mi17.2 sq mi
3Bond County17005380.3 sq mi2.5 sq mi
4Boone County17007280.7 sq mi1.3 sq mi
5Brown County17009305.7 sq mi1.6 sq mi
6Bureau County17011869.1 sq mi4.4 sq mi
7Calhoun County17013253.8 sq mi29.7 sq mi
8Carroll County17015445.4 sq mi21.6 sq mi
9Cass County17017375.8 sq mi7.9 sq mi
10Champaign County17019996.1 sq mi2.4 sq mi
11Christian County17021709.5 sq mi6.3 sq mi
12Clark County17023501.4 sq mi3.4 sq mi
13Clay County17025468.4 sq mi1.2 sq mi
14Clinton County17027473.9 sq mi29.2 sq mi
15Coles County17029508.3 sq mi1.8 sq mi
16Cook County17031944.9 sq mi689.7 sq mi
17Crawford County17033443.6 sq mi2.2 sq mi
18Cumberland County17035345.9 sq mi1 sq mi
19De Witt County17039397.6 sq mi7.5 sq mi
20DeKalb County17037631.3 sq mi3.3 sq mi
21Douglas County17041416.6 sq mi0.6 sq mi
22DuPage County17043327.9 sq mi8.5 sq mi
23Edgar County17045623.3 sq mi0.6 sq mi
24Edwards County17047222.4 sq mi0.3 sq mi
25Effingham County17049478.8 sq mi1.2 sq mi
26Fayette County17051716.5 sq mi8.8 sq mi
27Ford County17053485.6 sq mi0.6 sq mi
28Franklin County17055408.9 sq mi22.5 sq mi
29Fulton County17057865.7 sq mi16.9 sq mi
30Gallatin County17059322.9 sq mi5.2 sq mi
31Greene County17061543.1 sq mi3.3 sq mi
32Grundy County17063418.1 sq mi12.4 sq mi
33Hamilton County17065434.7 sq mi1.2 sq mi
34Hancock County17067793.7 sq mi20.7 sq mi
35Hardin County17069177.4 sq mi4 sq mi
36Henderson County17071378.8 sq mi16.4 sq mi
37Henry County17073823.2 sq mi2.5 sq mi
38Iroquois County170751,117.4 sq mi1.6 sq mi
39Jackson County17077583.6 sq mi18.6 sq mi
40Jasper County17079494.6 sq mi3.6 sq mi
41Jefferson County17081571.2 sq mi12.6 sq mi
42Jersey County17083369.6 sq mi7.9 sq mi
43Jo Daviess County17085600.9 sq mi17.7 sq mi
44Johnson County17087343.7 sq mi4.9 sq mi
45Kane County17089519.4 sq mi4.8 sq mi
46Kankakee County17091676.5 sq mi4.8 sq mi
47Kendall County17093320.2 sq mi2 sq mi
48Knox County17095716.4 sq mi3.4 sq mi
49Lake County17097443.7 sq mi924.7 sq mi
50LaSalle County170991,135.1 sq mi13.1 sq mi
51Lawrence County17101372.2 sq mi2 sq mi
52Lee County17103724.8 sq mi3.8 sq mi
53Livingston County171051,043.6 sq mi2.3 sq mi
54Logan County17107618.1 sq mi0.9 sq mi
55Macon County17115580.5 sq mi5.2 sq mi
56Macoupin County17117863 sq mi4.7 sq mi
57Madison County17119715.5 sq mi24.4 sq mi
58Marion County17121572.5 sq mi3.6 sq mi
59Marshall County17123386.8 sq mi11.7 sq mi
60Mason County17125539.4 sq mi24.2 sq mi
61Massac County17127237.2 sq mi4.9 sq mi
62McDonough County17109589.3 sq mi0.8 sq mi
63McHenry County17111603.4 sq mi7.7 sq mi
64McLean County171131,183.2 sq mi3 sq mi
65Menard County17129314.4 sq mi1 sq mi
66Mercer County17131561.2 sq mi7.5 sq mi
67Monroe County17133385.3 sq mi13 sq mi
68Montgomery County17135703.8 sq mi6 sq mi
69Morgan County17137569 sq mi3.5 sq mi
70Moultrie County17139336 sq mi8.5 sq mi
71Ogle County17141758.7 sq mi4.8 sq mi
72Peoria County17143618.7 sq mi11.6 sq mi
73Perry County17145441.9 sq mi5.1 sq mi
74Piatt County17147439.2 sq mi0.3 sq mi
75Pike County17149831.4 sq mi17.5 sq mi
76Pope County17151368.9 sq mi5.7 sq mi
77Pulaski County17153199.3 sq mi3.8 sq mi
78Putnam County17155160.1 sq mi12 sq mi
79Randolph County17157575.4 sq mi21.7 sq mi
80Richland County17159360 sq mi1.9 sq mi
81Rock Island County17161427.5 sq mi23.8 sq mi
82Saline County17165380 sq mi6.9 sq mi
83Sangamon County17167868.2 sq mi8.8 sq mi
84Schuyler County17169437.3 sq mi4.1 sq mi
85Scott County17171250.8 sq mi1.9 sq mi
86Shelby County17173758.5 sq mi9.6 sq mi
87St. Clair County17163657.7 sq mi16.1 sq mi
88Stark County17175288.1 sq mi0.3 sq mi
89Stephenson County17177564.2 sq mi0.5 sq mi
90Tazewell County17179646.5 sq mi11.5 sq mi
91Union County17181413.4 sq mi8.7 sq mi
92Vermilion County17183898.3 sq mi2.9 sq mi
93Wabash County17185223.3 sq mi4.2 sq mi
94Warren County17187542.4 sq mi0.7 sq mi
95Washington County17189562.6 sq mi1.3 sq mi
96Wayne County17191713.8 sq mi1.6 sq mi
97White County17193495 sq mi6.9 sq mi
98Whiteside County17195684.1 sq mi12.3 sq mi
99Will County17197835.9 sq mi13.3 sq mi
100Williamson County17199420.2 sq mi24.1 sq mi
101Winnebago County17201513 sq mi6.1 sq mi
102Woodford County17203527.6 sq mi15.4 sq mi

How to read and use this map

County lines are administrative boundaries, not postal routes. A mailing address can use a city name associated with a neighboring area, and ZIP codes can cross county lines. When you need to identify a county for an address, confirm it with an official geocoder or local government source.

For classroom or planning use, download a PDF from the controls above. Labelled exports use numbered callouts for crowded areas; numbered quiz maps match the alphabetical county list. SVG files keep the boundary lines sharp at larger paper sizes.

Frequently asked questions

How many counties are in Illinois?

Illinois has 102 counties in the U.S. Census Bureau’s 2025 cartographic boundary file.

Can I print this Illinois county map?

Yes. Choose Download / print and select PDF for a landscape Letter page, PNG for an image, or SVG for editable vector artwork. Because the map is SVG, its boundary lines stay sharp when scaled.

What is the largest county in Illinois?

McLean County is the largest by land area in this dataset at 1,183.2 square miles. This is an area ranking, not a population ranking.

What is the smallest county in Illinois?

Putnam County is the smallest by land area in this dataset at 160.1 square miles.

Are these legal survey boundaries?

No. This is a generalized reference map. Property, parcel, election, and legal boundary questions should be checked with the relevant state or local agency.

Map source

U.S. Census Bureau, 2025 Cartographic Boundary File, Counties, 1:5,000,000. Land and water area fields are supplied in the same file and converted from square meters to square miles. Accessed September 27, 2026.