The U.S. currently has 47 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated 14 combined statistical areas, 12 metropolitan statistical areas, and 21 micropolitan statistical areas in Illinois. As of 2025, the largest of these is the Chicago–Naperville, IL-IN-WI CSA, comprising the area around Illinois' largest city, Chicago.
+The 47 United States statistical areas and 102 counties of the State of IllinoisCombined statistical area2025 population (est.)Core-based statistical area2025 population (est.)County2025 population (est.)Metropolitan division2025 population (est.)Chicago–Naperville, IL-IN-WI CSA9,965,2928,956,807 ()Chicago–Naperville–Elgin, IL-IN MSA9,434,1238,705,380 (IL)Cook County, Illinois5,194,625Chicago–Naperville–Schaumburg, IL MD7,212,979DuPage County, Illinois934,298Will County, Illinois712,253McHenry County, Illinois317,751Grundy County, Illinois54,052Kane County, Illinois525,757Elgin, IL MD773,062Kendall County, Illinois145,470DeKalb County, Illinois101,835Lake County, Indiana504,612Lake County–Porter County–Jasper County, IN MD728,743Porter County, Indiana176,049Jasper County, Indiana33,894Newton County, Indiana14,188Lake County, Illinois719,339Lake County, IL MD719,339Kenosha, WI MSA168,448Kenosha County, Wisconsin168,448noneOttawa, IL μSA145,902LaSalle County, Illinois107,773Bureau County, Illinois32,510Putnam County, Illinois5,619Michigan City–La Porte, IN MSA111,294LaPorte County, Indiana111,294Kankakee, IL MSA105,525Kankakee County, Illinois105,525St. Louis–St. Charles–Farmington, MO-IL CSA2,918,612708,335 (IL)St. Louis, MO-IL MSA2,814,421671,953 (IL)St. Louis County, Missouri990,911St. Charles County, Missouri426,499City of St. Louis, Missouri278,144Madison County, Illinois263,110St. Clair County, Illinois250,708Jefferson County, Missouri233,132Franklin County, Missouri108,090Lincoln County, Missouri66,676Macoupin County, Illinois43,748Warren County, Missouri39,016Clinton County, Illinois37,128Monroe County, Illinois34,840Jersey County, Illinois21,160Bond County, Illinois16,959Calhoun County, Illinois4,300Farmington, MO μSA67,809Saint Francois County, Missouri67,809Centralia, IL μSA36,382Marion County, Illinois36,382Rockford–Freeport–Rochelle, IL CSA431,861Rockford, IL MSA337,242Winnebago County, Illinois283,674Boone County, Illinois53,568Rochelle, IL μSA51,399Ogle County, Illinois51,399Freeport, IL μSA43,220Stephenson County, Illinois43,220Peoria–Canton, IL CSA396,406Peoria, IL MSA363,505Peoria County, Illinois178,553Tazewell County, Illinois130,049Woodford County, Illinois38,111Marshall County, Illinois11,473Stark County, Illinois5,319Canton, IL μSA32,901Fulton County, Illinois32,901Champaign–Urbana–Danville, IL CSA311,238Champaign–Urbana, IL MSA239,979Champaign County, Illinois209,972Piatt County, Illinois16,791Ford County, Illinois13,216Danville, IL μSA71,259Vermilion County, Illinois71,259Springfield–Jacksonville–Lincoln, IL CSA304,039Springfield, IL MSA206,033Sangamon County, Illinois194,170Menard County, Illinois11,863Jacksonville, IL μSA37,381Morgan County, Illinois32,515Scott County, Illinois4,866Taylorville, IL μSA33,443Christian County, Illinois33,443Lincoln, IL μSA27,182Logan County, Illinois27,182Bloomington–Pontiac, IL CSA206,476Bloomington, IL MSA171,419McLean County, Illinois171,419Pontiac, IL μSA35,057Livingston County, Illinois35,057Davenport–Moline, IA-IL CSA468,307205,193 (IL)Davenport–Moline–Rock Island, IA-IL MSA380,452205,193 (IL)Scott County, Iowa175,259Rock Island County, Illinois141,869Henry County, Illinois48,095Mercer County, Illinois15,229Clinton, IA μSA46,002Clinton County, Iowa46,002Muscatine, IA μSA41,853Muscatine County, Iowa41,853Carbondale–Marion–Herrin, IL CSA119,726Marion–Herrin, IL μSA67,225Williamson County, Illinois67,225Carbondale, IL μSA52,501Jackson County, Illinois52,501noneDecatur, IL MSA99,300Macon County, Illinois99,300Dixon–Sterling, IL CSA87,035Sterling, IL μSA54,121Whiteside County, Illinois54,121Dixon, IL μSA32,914Lee County, Illinois32,914Quincy–Hannibal, IL-MO CSA113,11564,267 (IL)Quincy, IL-MO μSA74,14664,267 (IL)Adams County, Illinois64,267Lewis County, Missouri9,879Hannibal, MO μSA38,969Marion County, Missouri28,525Ralls County, Missouri10,444noneGalesburg, IL μSA47,767Knox County, Illinois47,767Charleston–Mattoon, IL μSA46,607Coles County, Illinois46,607Effingham, IL μSA44,727Effingham County, Illinois34,519Cumberland County, Illinois10,208Mount Vernon, IL μSA36,147Jefferson County, Illinois36,147Macomb, IL μSA25,916McDonough County, Illinois25,916Paducah–Mayfield, KY-IL CSA139,30913,502 (IL)Paducah, KY-IL MSA102,25913,502 (IL)McCracken County, Kentucky67,553Massac County, Illinois13,502Livingston County, Kentucky8,863Ballard County, Kentucky7,594Carlisle County, Kentucky4,747Mayfield, KY μSA37,050Graves County, Kentucky37,050Burlington–Fort Madison, IA-IL CSA76,3675,984 (IL)Burlington, IA-IL μSA44,0615,984 (IL)Des Moines County, Iowa38,077Henderson County, Illinois5,984Fort Madison, IA μSA32,306Lee County, Iowa32,306Cape Girardeau–Sikeston, MO-IL CSA149,1934,570 (IL)Cape Girardeau, MO-IL MSA99,2154,570 (IL)Cape Girardeau County, Missouri83,999Bollinger County, Missouri10,646Alexander County, Illinois4,570Sikeston, MO μSA49,978Scott County, Missouri37,975Mississippi County, Missouri12,003noneFranklin County, Illinois36,916Randolph County, Illinois29,921Montgomery County, Illinois28,076Iroquois County, Illinois26,150Saline County, Illinois22,772Jo Daviess County, Illinois21,594Fayette County, Illinois20,790Shelby County, Illinois20,576Perry County, Illinois20,160Douglas County, Illinois19,880Crawford County, Illinois18,648Hancock County, Illinois16,803Union County, Illinois16,656Edgar County, Illinois16,323Warren County, Illinois16,222Wayne County, Illinois15,882Carroll County, Illinois15,419Richland County, Illinois15,219DeWitt County, Illinois15,118Clark County, Illinois15,114Moultrie County, Illinois14,371Pike County, Illinois14,231Lawrence County, Illinois13,790Washington County, Illinois13,564Johnson County, Illinois13,363White County, Illinois13,250Clay County, Illinois12,793Cass County, Illinois12,463Mason County, Illinois12,411Greene County, Illinois11,313Wabash County, Illinois10,907Jasper County, Illinois9,032Hamilton County, Illinois7,859Schuyler County, Illinois6,657Brown County, Illinois6,401Edwards County, Illinois5,898Pulaski County, Illinois4,820Gallatin County, Illinois4,616Pope County, Illinois3,672Hardin County, Illinois3,588State of Illinois12,719,141
+The 32 core-based statistical areas of the State of Illinois2025 rankCore-based statistical areaPopulation2025 estimateChange2020 CensusChange2010 CensusChicago–Naperville–Elgin, IL-IN MSA (IL)St. Louis, MO-IL MSA (IL)Peoria, IL MSARockford, IL MSAChampaign–Urbana, IL MSASpringfield, IL MSADavenport–Moline–Rock Island, IA-IL MSA (IL)Bloomington, IL MSAOttawa, IL μSAKankakee, IL MSADecatur, IL MSADanville, IL μSAMarion–Herrin, IL μSAQuincy, IL-MO μSA (IL)Sterling, IL μSACarbondale, IL μSARochelle, IL μSAGalesburg, IL μSACharleston–Mattoon, IL μSAEffingham, IL μSAFreeport, IL μSAJacksonville, IL μSACentralia, IL μSAMount Vernon, IL μSAPontiac, IL μSATaylorville, IL μSACanton, IL μSALincoln, IL μSAMacomb, IL μSAPaducah, KY-IL μSA (IL)Burlington, IA-IL μSA (IL)Cape Girardeau, MO-IL μSA (IL)Burlington, IA-IL μSACape Girardeau, MO-IL μSAChicago–Naperville–Elgin, IL-IN MSADavenport–Moline–Rock Island, IA-IL MSAPaducah, KY-IL μSAQuincy, IL-MO μSASt. Louis, MO-IL MSA
+The 14 combined statistical areas of the State of Illinois2025 rankCombined statistical areaPopulation2025 estimateChange2020 CensusChange2010 CensusChicago–Naperville, IL-IN-WI CSA (IL)St. Louis–St. Charles–Farmington, MO-IL CSA (IL)Rockford–Freeport–Rochelle, IL CSAPeoria–Canton, IL CSAChampaign–Urbana–Danville, IL CSASpringfield–Jacksonville–Lincoln, IL CSABloomington–Pontiac, IL CSADavenport–Moline, IA-IL CSA (IL)Carbondale–Marion–Herrin, IL CSADixon–Sterling, IL CSAQuincy–Hannibal, IL-MO CSA (IL)Paducah–Mayfield, KY-IL CSA (IL)Burlington–Fort Madison, IA-IL CSA (IL)Cape Girardeau–Sikeston, MO-IL CSA (IL)Burlington–Fort Madison, IA-IL CSACape Girardeau–Sikeston, MO-IL CSAChicago–Naperville, IL-IN-WI CSADavenport–Moline, IA-IL CSAPaducah–Mayfield, KY-IL CSAQuincy–Hannibal, IL-MO CSASt. Louis–St. Charles–Farmington, MO-IL CSA
See also
Geography of Illinois Demographics of Illinois
Notes
References
External links
Office of Management and Budget United States Census Bureau