Data / Rankings / Housing units / Counties in Illinois

Counties in Illinois by housing units

Cook County had the highest housing units of 102 counties in 2021, at 2.25 million. Hardin County had the lowest, at 2,239. The median was 12,281 and the figure for Illinois was 5.41 million. Source: the U.S. Census Bureau.

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Highest2,253,936Cook County
Lowest2,239Hardin County
Median12,281102 counties
Illinois5,412,995History

Map of counties, 2021

Adams County: 30,225 countAlexander County: 3,059 countBond County: 6,902 countBoone County: 20,138 countBrown County: 2,346 countBureau County: 15,615 countCalhoun County: 2,344 countCarroll County: 8,195 countCass County: 5,702 countChampaign County: 92,663 countChristian County: 15,242 countClark County: 7,378 countClay County: 6,171 countClinton County: 15,575 countColes County: 22,852 countCook County: 2,253,936 countCrawford County: 8,497 countCumberland County: 4,736 countDeKalb County: 41,289 countDe Witt County: 7,350 countDouglas County: 8,463 countDuPage County: 364,157 countEdgar County: 8,306 countEdwards County: 3,053 countEffingham County: 15,237 countFayette County: 8,887 countFord County: 6,281 countFranklin County: 18,521 countFulton County: 15,884 countGallatin County: 2,528 countGreene County: 5,858 countGrundy County: 21,046 countHamilton County: 3,847 countHancock County: 8,980 countHardin County: 2,239 countHenderson County: 3,423 countHenry County: 22,204 countIroquois County: 12,865 countJackson County: 27,898 countJasper County: 4,235 countJefferson County: 16,657 countJersey County: 9,817 countJo Daviess County: 13,425 countJohnson County: 5,534 countKane County: 187,852 countKankakee County: 45,288 countKendall County: 44,443 countKnox County: 23,839 countLake County: 268,508 countLaSalle County: 49,825 countLawrence County: 6,361 countLee County: 14,999 countLivingston County: 15,925 countLogan County: 11,981 countMcDonough County: 13,714 countMcHenry County: 119,465 countMcLean County: 74,487 countMacon County: 49,832 countMacoupin County: 21,114 countMadison County: 118,518 countMarion County: 17,470 countMarshall County: 5,835 countMason County: 6,688 countMassac County: 6,840 countMenard County: 5,608 countMercer County: 7,299 countMonroe County: 14,438 countMontgomery County: 12,581 countMorgan County: 15,082 countMoultrie County: 6,172 countOgle County: 22,637 countPeoria County: 84,914 countPerry County: 9,166 countPiatt County: 7,359 countPike County: 7,332 countPope County: 2,370 countPulaski County: 2,876 countPutnam County: 3,069 countRandolph County: 13,425 countRichland County: 7,381 countRock Island County: 66,667 countSt. Clair County: 115,125 countSaline County: 11,593 countSangamon County: 92,702 countSchuyler County: 3,342 countScott County: 2,403 countShelby County: 10,075 countStark County: 2,588 countStephenson County: 21,449 countTazewell County: 58,606 countUnion County: 7,860 countVermilion County: 34,626 countWabash County: 5,418 countWarren County: 7,613 countWashington County: 6,428 countWayne County: 7,707 countWhite County: 6,805 countWhiteside County: 25,872 countWill County: 249,401 countWilliamson County: 31,674 countWinnebago County: 125,111 countWoodford County: 15,677 count
  • Under 10K
  • 10K to 20K
  • 20K to 50K
  • 50K and over
count, 2021. Source: U.S. Census Bureau, American Community Survey 5-year estimates, table B25001: total housing units. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2021

Cook County: 2,253,936 countCook County2,253,936DuPage County: 364,157 countDuPage County364,157Lake County: 268,508 countLake County268,508Will County: 249,401 countWill County249,401Kane County: 187,852 countKane County187,852Winnebago County: 125,111 countWinnebago County125,111McHenry County: 119,465 countMcHenry County119,465Madison County: 118,518 countMadison County118,518St. Clair County: 115,125 countSt. Clair County115,125Sangamon County: 92,702 countSangamon County92,702Champaign County: 92,663 countChampaign County92,663Peoria County: 84,914 countPeoria County84,914McLean County: 74,487 countMcLean County74,487Rock Island County: 66,667 countRock Island County66,667Tazewell County: 58,606 countTazewell County58,606Macon County: 49,832 countMacon County49,832LaSalle County: 49,825 countLaSalle County49,825Kankakee County: 45,288 countKankakee County45,288Kendall County: 44,443 countKendall County44,443DeKalb County: 41,289 countDeKalb County41,289Vermilion County: 34,626 countVermilion County34,626Williamson County: 31,674 countWilliamson County31,674Adams County: 30,225 countAdams County30,225Jackson County: 27,898 countJackson County27,898Whiteside County: 25,872 countWhiteside County25,872Knox County: 23,839 countKnox County23,839Coles County: 22,852 countColes County22,852Ogle County: 22,637 countOgle County22,637Henry County: 22,204 countHenry County22,204Stephenson County: 21,449 countStephenson County21,449Macoupin County: 21,114 countMacoupin County21,114Grundy County: 21,046 countGrundy County21,046Boone County: 20,138 countBoone County20,138Franklin County: 18,521 countFranklin County18,521Marion County: 17,470 countMarion County17,470Jefferson County: 16,657 countJefferson County16,657Livingston County: 15,925 countLivingston County15,925Fulton County: 15,884 countFulton County15,884Woodford County: 15,677 countWoodford County15,677Bureau County: 15,615 countBureau County15,615Cook County: 2,253,936 countCook County2,253,936DuPage County: 364,157 countDuPage County364,157Lake County: 268,508 countLake County268,508Will County: 249,401 countWill County249,401Kane County: 187,852 countKane County187,852Winnebago County: 125,111 countWinnebago County125,111McHenry County: 119,465 countMcHenry County119,465Madison County: 118,518 countMadison County118,518St. Clair County: 115,125 countSt. Clair County115,125Sangamon County: 92,702 countSangamon County92,702Champaign County: 92,663 countChampaign County92,663Peoria County: 84,914 countPeoria County84,914McLean County: 74,487 countMcLean County74,487Rock Island County: 66,667 countRock Island County66,667Tazewell County: 58,606 countTazewell County58,606Macon County: 49,832 countMacon County49,832LaSalle County: 49,825 countLaSalle County49,825Kankakee County: 45,288 countKankakee County45,288Kendall County: 44,443 countKendall County44,443DeKalb County: 41,289 countDeKalb County41,289Vermilion County: 34,626 countVermilion County34,626Williamson County: 31,674 countWilliamson County31,674Adams County: 30,225 countAdams County30,225Jackson County: 27,898 countJackson County27,898Whiteside County: 25,872 countWhiteside County25,872Knox County: 23,839 countKnox County23,839Coles County: 22,852 countColes County22,852Ogle County: 22,637 countOgle County22,637Henry County: 22,204 countHenry County22,204Stephenson County: 21,449 countStephenson County21,449Macoupin County: 21,114 countMacoupin County21,114Grundy County: 21,046 countGrundy County21,046Boone County: 20,138 countBoone County20,138Franklin County: 18,521 countFranklin County18,521Marion County: 17,470 countMarion County17,470Jefferson County: 16,657 countJefferson County16,657Livingston County: 15,925 countLivingston County15,925Fulton County: 15,884 countFulton County15,884Woodford County: 15,677 countWoodford County15,677Bureau County: 15,615 countBureau County15,615
count. Source: U.S. Census Bureau, American Community Survey 5-year estimates, table B25001: total housing units. Retrieved 2026-10-12.

Full ranking

RankCounties2021
count
1Cook County2,253,936
2DuPage County364,157
3Lake County268,508
4Will County249,401
5Kane County187,852
6Winnebago County125,111
7McHenry County119,465
8Madison County118,518
9St. Clair County115,125
10Sangamon County92,702
11Champaign County92,663
12Peoria County84,914
13McLean County74,487
14Rock Island County66,667
15Tazewell County58,606
16Macon County49,832
17LaSalle County49,825
18Kankakee County45,288
19Kendall County44,443
20DeKalb County41,289
21Vermilion County34,626
22Williamson County31,674
23Adams County30,225
24Jackson County27,898
25Whiteside County25,872
26Knox County23,839
27Coles County22,852
28Ogle County22,637
29Henry County22,204
30Stephenson County21,449
31Macoupin County21,114
32Grundy County21,046
33Boone County20,138
34Franklin County18,521
35Marion County17,470
36Jefferson County16,657
37Livingston County15,925
38Fulton County15,884
39Woodford County15,677
40Bureau County15,615
41Clinton County15,575
42Christian County15,242
43Effingham County15,237
44Morgan County15,082
45Lee County14,999
46Monroe County14,438
47McDonough County13,714
48Jo Daviess County13,425
48Randolph County13,425
50Iroquois County12,865
51Montgomery County12,581
52Logan County11,981
53Saline County11,593
54Shelby County10,075
55Jersey County9,817
56Perry County9,166
57Hancock County8,980
58Fayette County8,887
59Crawford County8,497
60Douglas County8,463
61Edgar County8,306
62Carroll County8,195
63Union County7,860
64Wayne County7,707
65Warren County7,613
66Richland County7,381
67Clark County7,378
68Piatt County7,359
69De Witt County7,350
70Pike County7,332
71Mercer County7,299
72Bond County6,902
73Massac County6,840
74White County6,805
75Mason County6,688
76Washington County6,428
77Lawrence County6,361
78Ford County6,281
79Moultrie County6,172
80Clay County6,171
81Greene County5,858
82Marshall County5,835
83Cass County5,702
84Menard County5,608
85Johnson County5,534
86Wabash County5,418
87Cumberland County4,736
88Jasper County4,235
89Hamilton County3,847
90Henderson County3,423
91Schuyler County3,342
92Putnam County3,069
93Alexander County3,059
94Edwards County3,053
95Pulaski County2,876
96Stark County2,588
97Gallatin County2,528
98Scott County2,403
99Pope County2,370
100Brown County2,346
101Calhoun County2,344
102Hardin County2,239

Other periods

About this ranking

All housing units, occupied and vacant: houses, apartments, mobile homes and rooms intended as separate living quarters. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

A survey estimate averaged over five years, not a count on one date.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. American Community Survey 5-year estimates, table B25001: total housing units. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). American Community Survey 5-year estimates, table B25001: total housing units (Counties in Illinois by housing units, 2021) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat

MLA 9

American Community Survey 5-year estimates, table B25001: total housing units, Counties in Illinois by housing units, 2021. U.S. Census Bureau, 29 Jan. 2026, https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Invokely, https://invokely.ai/rankings/housing-units/illinois-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. American Community Survey 5-year estimates, table B25001: total housing units. Counties in Illinois by housing units, 2021. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Also distributed by Invokely, https://invokely.ai/rankings/housing-units/illinois-counties?period=2021.

Harvard

U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B25001: total housing units, Counties in Illinois by housing units, 2021 [Dataset]. Available at: https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat, via Invokely: https://invokely.ai/rankings/housing-units/illinois-counties?period=2021 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_illinois_by_2021,
  author = {{U.S. Census Bureau}},
  title = {{American Community Survey 5-year estimates, table B25001: total housing units: Counties in Illinois by housing units, 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/housing-units/illinois-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B25001: total housing units. https://www2.census.gov/programs-surveys/acs/summary\_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - American Community Survey 5-year estimates, table B25001: total housing units: Counties in Illinois by housing units, 2021
PY  - 2026
DA  - 2026/01/29
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat
L2  - https://invokely.ai/rankings/housing-units/illinois-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/housing-units/illinois-counties?period=2021.
N1  - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B25001: total housing units. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25001.dat. Retrieved 2026-10-12.
ER  -
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Questions

Which county has the highest housing units?

Cook County, with 2.25 million in 2021, according to the U.S. Census Bureau.

Which county has the lowest housing units?

Hardin County, with 2,239 in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B25001: total housing units. Retrieved 2026-10-12.

Housing units: other rankings

Counties in Illinois: more rankings