Jersey County, Illinois
Jersey County, Illinois, has 21,160 residents (July 2025 estimate). Its county seat is Jerseyville. It uses Central Time and covers 370 sq mi (957 km²) of land.
- Resident population, July 2025
- 21,160
- Land area
- 370 sq mi (957 km²)
- County seat or government
- Jerseyville
- Time zone
- Central TimeUTC-06:00 in January; UTC-05:00 in July
- Median household income
- $80,361 ± $7,869
- Median home value
- $171,900 ± $12,525
- Median rent, with utilities
- $846 ± $43
- Homes lived in by their owners
- 80.5% ± 2.7 points
- County type
- County
- Metro or micro area
- St. Louis, MO-IL metro areaOutlying county
- Water area
- 7.85 sq mi (20.3 km²)
- State
- Illinois
- County code (FIPS)
- 17083
- Coordinates (central point)
- 39.080195, -90.361385
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 Jersey 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
- 6203515,892 people
- 6205212,237 people
- 620126,672 people
- 620371,814 people
- 620281,385 people
- 620221,088 people
- 62063795 people
- 62031517 people
- 62027516 people
- 62054315 people
- 62079292 people
- 6203071 people
12 ZIP Code areas overlap Jersey 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
We don’t have a website for this county yet. The US government’s local-office directory ↗ lists its offices. A geographic lookup cannot determine eligibility, tax liability or a court obligation.
Townships in Jersey County, largest first
- Jersey Township9,924 people
- Piasa Township3,085 people
- Elsah Township2,799 people
- Mississippi Township1,667 people
- Quarry Township1,062 people
- Otter Creek Township802 people
- Fidelity Township705 people
- English Township521 people
- Richwood Township413 people
- Ruyle Township154 people
- Rosedale Township142 people
People counts are American Community Survey 2020–2024 5-year estimates. All townships in Illinois, by county
School districts in Jersey County, largest first
- Alton Community Unit School District 1145,851 people
- Jersey Community Unit School District 10018,492 people
- Southwestern Community Unit School District 98,468 people
- Greenfield Community Unit School District 102,577 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.
- Jerseyville, Illinois (city)7,445 people
- Brighton, Illinois (village)2,306 people
- Grafton, Illinois (city)734 people
- Elsah, Illinois (village)708 people
- Medora, Illinois (village)316 people
- Fieldon, Illinois (village)200 people
- Otterville, Illinois (town)126 people
- Fidelity, Illinois (village)71 people
Bordering areas, nearest first
Distances are straight lines between map points.
- Calhoun County, Illinois17 mi west
- Greene County, Illinois19 mi north
- Macoupin County, Illinois27 mi northeast
- St. Charles County, Missouri27 mi southwest
- Madison County, Illinois30 mi southeast
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