Illinois 2020 Census Total Population By County
The total population of Illinois from the 2020 Census was 12,812,508, based on data from the US Census Bureau.
Cook County was the most populated county (5,275,541), followed by DuPage County (932,877), and then Lake County (714,342). On the other hand, the 3 counties that were least populated include: Hardin County (3,649), Pope County (3,763), and Calhoun County (4,437).
You can also see this information for other states and also for the US by state.
Hover over or click on the counties to see the number and percentage of Illinois population that lives in each county. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.
You can also see the population by county for the different racial groups as well as the different ethnicities in Illinois.
| County | Population | % of Illinois Pop. |
|---|---|---|
| Adams | 65737 | 0.51 |
| Alexander | 5240 | 0.04 |
| Bond | 16725 | 0.13 |
| Boone | 53448 | 0.42 |
| Brown | 6244 | 0.05 |
| Bureau | 33244 | 0.26 |
| Calhoun | 4437 | 0.04 |
| Carroll | 15702 | 0.12 |
| Cass | 13042 | 0.10 |
| Champaign | 205865 | 1.61 |
| Christian | 34032 | 0.27 |
| Clark | 15455 | 0.12 |
| Clay | 13288 | 0.10 |
| Clinton | 36899 | 0.29 |
| Coles | 46863 | 0.37 |
| Cook | 5275541 | 41.18 |
| Crawford | 18679 | 0.15 |
| Cumberland | 10450 | 0.08 |
| DeKalb | 100420 | 0.78 |
| De Witt | 15516 | 0.12 |
| Douglas | 19740 | 0.15 |
| DuPage | 932877 | 7.28 |
| Edgar | 16866 | 0.13 |
| Edwards | 6245 | 0.05 |
| Effingham | 34668 | 0.27 |
| Fayette | 21488 | 0.17 |
| Ford | 13534 | 0.11 |
| Franklin | 37804 | 0.30 |
| Fulton | 33609 | 0.26 |
| Gallatin | 4946 | 0.04 |
| Greene | 11985 | 0.09 |
| Grundy | 52533 | 0.41 |
| Hamilton | 7993 | 0.06 |
| Hancock | 17620 | 0.14 |
| Hardin | 3649 | 0.03 |
| Henderson | 6387 | 0.05 |
| Henry | 49284 | 0.39 |
| Iroquois | 27077 | 0.21 |
| Jackson | 52974 | 0.41 |
| Jasper | 9287 | 0.07 |
| Jefferson | 37113 | 0.29 |
| Jersey | 21512 | 0.17 |
| Jo Daviess | 22035 | 0.17 |
| Johnson | 13308 | 0.10 |
| Kane | 516522 | 4.03 |
| Kankakee | 107502 | 0.84 |
| Kendall | 131869 | 1.03 |
| Knox | 49967 | 0.39 |
| Lake | 714342 | 5.58 |
| LaSalle | 109658 | 0.86 |
| Lawrence | 15280 | 0.12 |
| Lee | 34145 | 0.27 |
| Livingston | 35815 | 0.28 |
| Logan | 27987 | 0.22 |
| McDonough | 27238 | 0.21 |
| McHenry | 310229 | 2.42 |
| McLean | 170954 | 1.33 |
| Macon | 103998 | 0.81 |
| Macoupin | 44967 | 0.35 |
| Madison | 265859 | 2.08 |
| Marion | 37729 | 0.29 |
| Marshall | 11742 | 0.09 |
| Mason | 13086 | 0.10 |
| Massac | 14169 | 0.11 |
| Menard | 12297 | 0.10 |
| Mercer | 15699 | 0.12 |
| Monroe | 34962 | 0.27 |
| Montgomery | 28288 | 0.22 |
| Morgan | 32915 | 0.26 |
| Moultrie | 14526 | 0.11 |
| Ogle | 51788 | 0.40 |
| Peoria | 181830 | 1.42 |
| Perry | 20945 | 0.16 |
| Piatt | 16673 | 0.13 |
| Pike | 14739 | 0.12 |
| Pope | 3763 | 0.03 |
| Pulaski | 5193 | 0.04 |
| Putnam | 5637 | 0.04 |
| Randolph | 30163 | 0.24 |
| Richland | 15813 | 0.12 |
| Rock Island | 144672 | 1.13 |
| St. Clair | 257400 | 2.01 |
| Saline | 23768 | 0.19 |
| Sangamon | 196343 | 1.53 |
| Schuyler | 6902 | 0.05 |
| Scott | 4949 | 0.04 |
| Shelby | 20990 | 0.16 |
| Stark | 5400 | 0.04 |
| Stephenson | 44630 | 0.35 |
| Tazewell | 131343 | 1.02 |
| Union | 17244 | 0.14 |
| Vermilion | 74188 | 0.58 |
| Wabash | 11361 | 0.09 |
| Warren | 16835 | 0.13 |
| Washington | 13761 | 0.11 |
| Wayne | 16179 | 0.13 |
| White | 13877 | 0.11 |
| Whiteside | 55691 | 0.44 |
| Will | 696355 | 5.44 |
| Williamson | 67153 | 0.52 |
| Winnebago | 285350 | 2.23 |
| Woodford | 38467 | 0.30 |