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County | 2024 Pop. | Change (2020) | Area (mi²) | Density (/mi²) | Location |
---|---|---|---|---|---|
Cook County | 5,062,578 | -3.82% | 365 | 5,357 | |
DuPage County | 920,762 | -1.13% | 127 | 2,807 | |
Lake County | 707,621 | -0.79% | 171 | 1,594 | |
Will County | 703,410 | 0.94% | 323 | 841 | |
Kane County | 515,825 | -0.07% | 200 | 994 | |
McHenry County | 314,042 | 1.34% | 233 | 521 | |
Winnebago County | 280,302 | -1.62% | 198 | 546 | |
Madison County | 261,932 | -1.4% | 276 | 366 | |
St. Clair County | 249,771 | -2.75% | 254 | 380 | |
Champaign County | 205,119 | -0.26% | 384 | 206 | |
Sangamon County | 192,831 | -1.69% | 335 | 222 | |
Peoria County | 177,026 | -2.37% | 239 | 286 | |
McLean County | 169,964 | -0.58% | 457 | 144 | |
Kendall County | 142,458 | 7.63% | 124 | 445 | |
Rock Island County | 140,913 | -2.39% | 165 | 330 | |
Tazewell County | 129,472 | -1.23% | 249 | 200 | |
LaSalle County | 108,437 | -0.89% | 438 | 96 | |
Kankakee County | 105,882 | -1.29% | 261 | 157 | |
DeKalb County | 100,353 | 0.08% | 244 | 159 | |
Macon County | 99,849 | -3.76% | 224 | 172 | |
Vermilion County | 71,201 | -3.79% | 347 | 79 | |
Williamson County | 66,868 | -0.37% | 162 | 159 | |
Adams County | 64,326 | -1.96% | 330 | 75 | |
Whiteside County | 54,441 | -2.02% | 264 | 80 | |
Grundy County | 54,007 | 2.84% | 161 | 129 | |
Boone County | 53,336 | -0.01% | 108 | 190 | |
Jackson County | 51,805 | -2.05% | 225 | 89 | |
Ogle County | 51,185 | -0.98% | 293 | 67 | |
Henry County | 48,300 | -1.76% | 318 | 59 | |
Knox County | 48,202 | -3.19% | 276 | 67 | |
Coles County | 45,774 | -2.11% | 196 | 90 | |
Macoupin County | 43,913 | -2.1% | 333 | 51 | |
Stephenson County | 42,654 | -4.15% | 218 | 76 | |
Woodford County | 38,393 | -0.05% | 204 | 73 | |
Franklin County | 37,061 | -1.69% | 158 | 91 | |
Clinton County | 36,633 | -0.73% | 183 | 77 | |
Marion County | 36,441 | -3.22% | 221 | 64 | |
Jefferson County | 36,221 | -2.09% | 220 | 63 | |
Livingston County | 35,123 | -1.87% | 403 | 34 | |
Monroe County | 34,913 | -0.11% | 149 | 91 | |
Effingham County | 34,362 | -0.98% | 185 | 72 | |
Lee County | 33,370 | -2.03% | 280 | 46 | |
Christian County | 33,066 | -2.63% | 274 | 47 | |
Bureau County | 32,631 | -1.69% | 335 | 38 | |
Fulton County | 32,147 | -4% | 334 | 37 | |
Morgan County | 31,982 | -2.63% | 220 | 56 | |
Randolph County | 29,604 | -1.62% | 222 | 51 | |
Logan County | 27,514 | -1.43% | 239 | 45 | |
Montgomery County | 27,425 | -2.76% | 272 | 39 | |
McDonough County | 26,764 | -1.24% | 227 | 45 | |
Iroquois County | 25,779 | -4.47% | 431 | 23 | |
Saline County | 22,694 | -4.2% | 147 | 60 | |
Jo Daviess County | 21,667 | -1.77% | 232 | 36 | |
Fayette County | 21,058 | -2.01% | 276 | 29 | |
Jersey County | 20,991 | -2.34% | 143 | 57 | |
Perry County | 20,494 | -1.88% | 171 | 46 | |
Shelby County | 20,426 | -2.36% | 293 | 27 | |
Douglas County | 19,591 | -0.88% | 161 | 47 | |
Crawford County | 18,105 | -2.93% | 171 | 41 | |
Hancock County | 17,118 | -2.42% | 306 | 22 | |
Piatt County | 16,753 | 0.43% | 169 | 38 | |
Union County | 16,562 | -3.62% | 159 | 40 | |
Bond County | 16,364 | -1.92% | 147 | 43 | |
Edgar County | 16,283 | -3% | 240 | 26 | |
Warren County | 16,010 | -4.82% | 209 | 30 | |
Wayne County | 15,679 | -2.77% | 276 | 22 | |
Carroll County | 15,473 | -1.27% | 172 | 35 | |
Mercer County | 15,441 | -1.22% | 217 | 28 | |
Richland County | 15,421 | -2.34% | 139 | 43 | |
De Witt County | 15,365 | -0.62% | 154 | 39 | |
Clark County | 15,016 | -2.68% | 193 | 30 | |
Lawrence County | 14,735 | -3.49% | 144 | 40 | |
Moultrie County | 14,309 | -1.19% | 130 | 43 | |
Pike County | 14,185 | -3.11% | 321 | 17 | |
Massac County | 13,495 | -4.51% | 91 | 57 | |
Washington County | 13,449 | -2% | 217 | 24 | |
Johnson County | 13,261 | -0.43% | 133 | 39 | |
Ford County | 13,244 | -1.99% | 188 | 27 | |
White County | 13,207 | -4.35% | 191 | 27 | |
Clay County | 12,921 | -2.65% | 181 | 28 | |
Cass County | 12,554 | -3.36% | 145 | 33 | |
Mason County | 12,347 | -5.44% | 208 | 23 | |
Menard County | 11,836 | -3.54% | 121 | 38 | |
Marshall County | 11,695 | -0.19% | 149 | 30 | |
Greene County | 11,446 | -4.11% | 210 | 21 | |
Wabash County | 10,844 | -4.19% | 86 | 49 | |
Cumberland County | 10,214 | -2.1% | 134 | 30 | |
Jasper County | 9,116 | -1.35% | 191 | 18 | |
Hamilton County | 7,841 | -1.98% | 168 | 18 | |
Schuyler County | 6,713 | -2.26% | 169 | 15 | |
Brown County | 6,272 | 0.72% | 118 | 20 | |
Henderson County | 6,008 | -5.16% | 146 | 16 | |
Edwards County | 5,878 | -5.32% | 86 | 26 | |
Putnam County | 5,569 | -1.08% | 62 | 35 | |
Stark County | 5,123 | -4.81% | 111 | 18 | |
Pulaski County | 4,872 | -5.58% | 77 | 24 | |
Scott County | 4,649 | -5.91% | 97 | 19 | |
Alexander County | 4,549 | -11.99% | 91 | 19 | |
Gallatin County | 4,517 | -8.47% | 125 | 14 | |
Calhoun County | 4,281 | -2.86% | 98 | 17 | |
Pope County | 3,668 | -2.29% | 142 | 10 | |
Hardin County | 3,566 | -2.09% | 68 | 20 |
There are 102 counties in Illinois. In 2019, the most highly populated county within the state of Illinois is Cook County, home to the city of Chicago. With a population of 5,180,493, Cook County has seen a decrease in the total population of 0.36% since the last U.S. census was taken in 2010. Following Cook County, other large counties in Illinois are DuPage County (928,589), Lake County (700,832), Will County (692,310), and Kane County (534,216). Kane County reported the most significant population growth, increasing its population by 3.50%.
The county with the lowest population in the state of Illinois is Hardin County, which has a population of 3,910. Since the last census in 2010, Hardin County’s population has seen a decrease of 9.35%. Following behind Hardin County, other small counties in Illinois include Pope County (4,212), Calhoun County (4,802), and Scott County (4,926). Illinois has 72 counties with a population of less than 50,000; all but one (Monroe County) experienced a decline in population. Of the 15 counties with fewer than 10,000 residents, Alexander County experienced the most dramatic decrease with a growth rate of -26.15%.
Kendall County is the fastest-growing county in Illinois with a population growth rate of 10.87% to 127,915 residents. Following Kendall County, Champagne County (4.19%), Monroe County (4.05%), and Kane County (3.5%) also experienced an increase in residents. Only five other counties in Illinois had any increase in population since 2010. The county with the lowest growth rate in Illinois is Alexander County, which has seen a population decrease of 26.15%.
State | Counties |
---|---|
Texas | 254 |
Georgia | 159 |
Virginia | 133 |
Kentucky | 120 |
Missouri | 115 |
Kansas | 105 |
Illinois | 102 |
North Carolina | 100 |
Iowa | 99 |
Tennessee | 95 |
Nebraska | 93 |
Indiana | 92 |
Ohio | 88 |
Minnesota | 87 |
Michigan | 83 |
Mississippi | 82 |
Puerto Rico | 78 |
Oklahoma | 77 |
Arkansas | 75 |
Wisconsin | 72 |
Alabama | 67 |
Florida | 67 |
Pennsylvania | 67 |
South Dakota | 66 |
Colorado | 64 |
Louisiana | 64 |
New York | 62 |
California | 58 |
Montana | 56 |
West Virginia | 55 |
North Dakota | 53 |
South Carolina | 46 |
Idaho | 44 |
Washington | 39 |
Oregon | 36 |
New Mexico | 33 |
Alaska | 30 |
Utah | 29 |
Maryland | 24 |
Wyoming | 23 |
New Jersey | 21 |
Nevada | 17 |
Maine | 16 |
Arizona | 15 |
Massachusetts | 14 |
Vermont | 14 |
New Hampshire | 10 |
Connecticut | 9 |
Hawaii | 5 |
Rhode Island | 5 |
Delaware | 3 |
District of Columbia | 1 |