Johnson County, Illinois
Johnson County is a county in Illinois. Its county FIPS code is 17087. Use the boundary map and neighboring areas below to check the jurisdiction you need.
- Official code
- 17087
- Representative coordinates
- 37.460709, -88.882131
- County type
- County
- County seat or government
- Vienna
- Resident population, July 2025
- 13,363
- Land area
- 890.275 km²
- Water area
- 12.813 km²
- State
- Illinois
The representative point identifies this area. It is not a street address or a boundary survey.
Time zones in Johnson County
| Time zone | Local time and UTC offset | Next clock change |
|---|---|---|
| America/Chicago | UTC-06:00 in January; UTC-05:00 in July. Enable JavaScript for the live clock. | Enable JavaScript for upcoming changes. |
Listed zones overlap the mapped area. A point lookup can distinguish sides of a boundary. Your device’s zone may differ.
Census ZIP areas
62908 · 62912 · 62922 · 62923 · 62939 · 62943 · 62967 · 62972 · 62985 · 62995
These statistical areas overlap the boundary. They are not delivery assignments; confirm mailing details with USPS ZIP Code Lookup.
Official county information
Use the US government local-office directory ↗ to find the office responsible for your address. A county website has not been confidently matched here. A geographic lookup cannot determine eligibility, tax liability or a court obligation.
Cities, towns and communities
These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.
Areas sharing the mapped boundary
These areas touch this mapped boundary.
Before using this answer on a form
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Find the county at your current point, check its ZIP area, or find its physical time zone.