Carroll County, Illinois
Carroll County, Illinois, has 15,419 residents (July 2025 estimate). Its county seat is Mount Carroll. It uses Central Time and covers 445 sq mi (1,154 km²) of land.
- Resident population, July 2025
- 15,419
- Land area
- 445 sq mi (1,154 km²)
- County seat or government
- Mount Carroll
- Time zone
- Central TimeUTC-06:00 in January; UTC-05:00 in July
- Median household income
- $60,758 ± $2,707
- Median home value
- $114,500 ± $5,896
- Median rent, with utilities
- $818 ± $38
- Homes lived in by their owners
- 77.2% ± 2.1 points
- County type
- County
- Metro or micro area
- Outside any metro or micro areaNext to: Freeport, IL micro area, Sterling, IL micro area, Clinton, IA micro area, and Rochelle, IL micro area
- Water area
- 21.6 sq mi (55.9 km²)
- State
- Illinois
- County code (FIPS)
- 17015
- Coordinates (central point)
- 42.070900, -89.924190
These coordinates mark a central point for the area, not a street address. Income, home value, rent and homes lived in by their owners: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 13, 2026.
Time zones in Carroll County
| Time zone | Local time and UTC offset | Next clock change |
|---|---|---|
| Central TimeAmerica/Chicago | UTC-06:00 in January; UTC-05:00 in July. Enable JavaScript for the live clock. | Enable JavaScript for upcoming changes. |
Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.
ZIP Code areas, largest first
- 612706,912 people
- 610743,962 people
- 610643,757 people
- 610462,794 people
- 612852,728 people
- 610532,590 people
- 610621,840 people
- 610281,683 people
- 610511,469 people
- 610781,459 people
- 610141,067 people
11 ZIP Code areas overlap Carroll County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.
Official county information
Carroll County government website ↗ is the next stop for county offices, tax, voting, jury and records information. A geographic lookup cannot determine eligibility, tax liability or a court obligation.
Townships in Carroll County, largest first
- Savanna Township3,388 people
- York Township2,763 people
- Mount Carroll Township1,927 people
- Rock Creek-Lima Township1,891 people
- Cherry Grove-Shannon Township1,565 people
- Wysox Township1,427 people
- Fairhaven Township860 people
- Freedom Township672 people
- Washington Township341 people
- Woodland Township338 people
- Salem Township333 people
- Elkhorn Grove Township71 people
People counts are American Community Survey 2020–2024 5-year estimates. All townships in Illinois, by county
School districts in Carroll County, largest first
- West Carroll Community Unit School District 3149,166 people
- Eastland Community Unit School District 3084,377 people
- Chadwick-Milledgeville Community Unit School District 3992,750 people
- Pearl City Community Unit School District 2002,290 people
Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.
Cities, towns and communities, largest first
These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.
- Savanna, Illinois (city)2,816 people
- Thomson, Illinois (village)1,757 people
- Lanark, Illinois (city)1,541 people
- Mount Carroll, Illinois (city)1,501 people
- Milledgeville, Illinois (village)1,218 people
- Lake Carroll, Illinois (CDP)853 people
- Shannon, Illinois (village)772 people
- Chadwick, Illinois (village)591 people
Bordering areas, nearest first
Distances are straight lines between map points.
- Whiteside County, Illinois22 mi south
- Stephenson County, Illinois23 mi northeast
- Jo Daviess County, Illinois25 mi northwest
- Ogle County, Illinois31 mi east
- Clinton County, Iowa34 mi west
- Jackson County, Iowa34 mi west
Before using this answer on a form
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