Marshall County, Illinois
Marshall County is a county in Illinois. Its county FIPS code is 17123. Use the boundary map and neighboring areas below to check the jurisdiction you need.
- Official code
- 17123
- Representative coordinates
- 41.031119, -89.342371
- County type
- County
- County seat or government
- Lacon
- Resident population, July 2025
- 11,473
- Land area
- 1,001.865 km²
- Water area
- 30.344 km²
- State
- Illinois
The representative point identifies this area. It is not a street address or a boundary survey.
Time zones in Marshall 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
61321 · 61336 · 61358 · 61369 · 61375 · 61377 · 61421 · 61424 · 61479 · 61491 · 61523 · 61526 · 61537 · 61540 · 61541 · 61560 · 61565 · 61570 · 61760
These statistical areas overlap the boundary. They are not delivery assignments; confirm mailing details with USPS ZIP Code Lookup.
Official county information
Marshall 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.
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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