LaSalle County, Illinois

Time zones in LaSalle County

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

1. 6135023,713 people
2. 6136417,963 people
3. 6054811,721 people
4. 6130110,398 people
5. 6135410,290 people
6. 613428,543 people
7. 613417,692 people
8. 605515,058 people
9. 613484,375 people
10. 605524,285 people
11. 613603,610 people
12. 605413,342 people

29 ZIP Code areas overlap LaSalle 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

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.

Townships in LaSalle County, largest first

1. LaSalle Township13,287 people
2. Bruce Township11,794 people
3. Ottawa Township11,204 people
4. Peru Township10,070 people
5. South Ottawa Township8,322 people
6. Northville Township7,316 people
7. Mendota Township7,071 people
8. Manlius Township6,100 people
9. Mission Township4,054 people
10. Rutland Township3,589 people
11. Otter Creek Township2,642 people
12. Earl Township2,574 people

People counts are American Community Survey 2020–2024 5-year estimates. All townships in Illinois, by county

School districts in LaSalle County, largest first

1. Ottawa Township High School District 14030,670 people
2. LaSalle-Peru Township High School District 12028,052 people
3. Ottawa Elementary School District 14118,936 people
4. Streator Township High School District 4016,518 people
5. Streator Elementary School District 4414,924 people
6. Sandwich Community Unit School District 43013,374 people
7. Mendota Township High School District 28010,380 people
8. Mendota Community Consolidated School District 28910,085 people
9. Peru Elementary School District 1249,888 people
10. LaSalle Elementary School District 1229,121 people
11. Seneca Township High School District 1607,207 people
12. Fieldcrest Community Unit School District 66,096 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.

1. Ottawa, Illinois (city)18,447 people
2. Streator, Illinois (city)12,330 people
3. Peru, Illinois (city)9,775 people
4. LaSalle, Illinois (city)9,498 people
5. Mendota, Illinois (city)6,994 people
6. Lake Holiday, Illinois (CDP)5,641 people
7. Marseilles, Illinois (city)4,279 people
8. Oglesby, Illinois (city)3,570 people
9. Sheridan, Illinois (village)2,519 people
10. Seneca, Illinois (village)2,450 people
11. Earlville, Illinois (city)1,942 people
12. Somonauk, Illinois (village)1,569 people

See all 33 cities, towns and communities in LaSalle County, largest first

Bordering areas, nearest first

Distances are straight lines between map points.

1. Putnam County, Illinois24 mi southwest
2. Grundy County, Illinois25 mi east
3. Kendall County, Illinois29 mi northeast
4. Marshall County, Illinois32 mi southwest
5. Bureau County, Illinois34 mi west
6. Lee County, Illinois35 mi northwest
7. Livingston County, Illinois36 mi southeast
8. DeKalb County, Illinois39 mi north
9. Woodford County, Illinois42 mi southwest

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See this county on Census.gov ↗