LaSalle County, Illinois
LaSalle County is a county in Illinois. Its county FIPS code is 17099. Use the boundary map and neighboring areas below to check the jurisdiction you need.
- Official code
- 17099
- Representative coordinates
- 41.343341, -88.885931
- County type
- County
- County seat or government
- Ottawa
- Resident population, July 2025
- 107,773
- Land area
- 2,939.941 km²
- Water area
- 33.828 km²
- State
- Illinois
The representative point identifies this area. It is not a street address or a boundary survey.
Time zones in LaSalle 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
60470 · 60518 · 60531 · 60537 · 60541 · 60548 · 60549 · 60551 · 60552 · 60557 · 61301 · 61316 · 61321 · 61325 · 61332 · 61334 · 61341 · 61342 · 61348 · 61350 · 61354 · 61358 · 61360 · 61364 · 61370 · 61371 · 61372 · 61373 · 61377
These statistical areas overlap the boundary. They are not delivery assignments; confirm mailing details with USPS ZIP Code Lookup.
Official county information
LaSalle 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.
- Cedar Point village, IL
- Dalzell village, IL
- Dana village, IL
- Dayton CDP, IL
- Earlville city, IL
- Grand Ridge village, IL
- Harding CDP, IL
- Kangley village, IL
- Lake Holiday CDP, IL
- LaSalle city, IL
- Leland village, IL
- Leonore village, IL
- Lostant village, IL
- Marseilles city, IL
- Mendota city, IL
- Millington village, IL
- Naplate village, IL
- North Utica village, IL
- Oglesby city, IL
- Ottawa city, IL
- Peru city, IL
- Ransom village, IL
- Rutland village, IL
- Seneca village, IL
- Serena CDP, IL
- Sheridan village, IL
- Somonauk village, IL
- Streator city, IL
- Tonica village, IL
- Triumph CDP, IL
Areas sharing the mapped boundary
These areas touch this mapped boundary.
Before using this answer on a form
Use a precise point for address-level questions. A device accuracy circle can cross a boundary; confirm tax, voting or jury details with the responsible office.
Find the county at your current point, check its ZIP area, or find its physical time zone.