Illinois: Time Zones, Counties, Cities & Map

Metro and micro areas in Illinois, largest first

12 metro areas and 21 micro areas have counties in Illinois. 7 cross into another state; their populations are for the whole area. Populations are July 2025 estimates.

1. Chicago-Naperville-Elgin, IL-IN Metro Area9,434,123 people
2. St. Louis, MO-IL Metro Area2,814,421 people
3. Davenport-Moline-Rock Island, IA-IL Metro Area380,452 people
4. Peoria, IL Metro Area363,505 people
5. Rockford, IL Metro Area337,242 people
6. Champaign-Urbana, IL Metro Area239,979 people
7. Springfield, IL Metro Area206,033 people
8. Bloomington, IL Metro Area171,419 people
9. Ottawa, IL Micro Area145,902 people
10. Kankakee, IL Metro Area105,525 people
11. Paducah, KY-IL Metro Area102,259 people
12. Decatur, IL Metro Area99,300 people

Every metro and micro area in the US

Largest townships and precincts in Illinois

1. Rockford Township, Winnebago County169,035 people
2. Wheeling Township, Cook County153,991 people
3. Thornton Township, Cook County153,682 people
4. Worth Township, Cook County149,419 people
5. Downers Grove Township, DuPage County149,038 people
6. Proviso Township, Cook County147,690 people
7. Maine Township, Cook County137,069 people
8. Schaumburg Township, Cook County131,761 people
9. York Township, DuPage County127,667 people
10. Aurora Township, Kane County126,432 people
11. Milton Township, DuPage County119,372 people
12. Lisle Township, DuPage County118,895 people

All 1,650 townships and precincts in Illinois, by county

Counties and equivalents, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

1. Cook County, Illinois5,194,625 people
2. DuPage County, Illinois934,298 people
3. Lake County, Illinois719,339 people
4. Will County, Illinois712,253 people
5. Kane County, Illinois525,757 people
6. McHenry County, Illinois317,751 people
7. Winnebago County, Illinois283,674 people
8. Madison County, Illinois263,110 people
9. St. Clair County, Illinois250,708 people
10. Champaign County, Illinois209,972 people
11. Sangamon County, Illinois194,170 people
12. Peoria County, Illinois178,553 people

See all 102 counties and equivalents in Illinois, largest first

Cities, towns and communities, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

1. Chicago, Illinois (city)2,711,226 people
2. Aurora, Illinois (city)179,898 people
3. Naperville, Illinois (city)150,692 people
4. Joliet, Illinois (city)150,445 people
5. Rockford, Illinois (city)147,521 people
6. Elgin, Illinois (city)114,934 people
7. Springfield, Illinois (city)113,330 people
8. Peoria, Illinois (city)112,169 people
9. Champaign, Illinois (city)89,996 people
10. Waukegan, Illinois (city)89,076 people
11. Cicero, Illinois (town)82,797 people
12. Bloomington, Illinois (city)78,907 people

See all 1,461 cities, towns and communities in Illinois, largest first

ZIP Code areas, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

1. ZIP 60629108,324 people
2. ZIP 6061891,901 people
3. ZIP 6063289,107 people
4. ZIP 6064784,749 people
5. ZIP 6063984,240 people
6. ZIP 6080482,797 people
7. ZIP 6062381,277 people
8. ZIP 6060880,737 people
9. ZIP 6062576,760 people
10. ZIP 6061774,790 people
11. ZIP 6063473,885 people
12. ZIP 6008572,341 people

See all 1,397 ZIP Code areas in Illinois, largest first

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