Ottawa city, Illinois
Official LSAD Designation: Ottawa city • Census GEOID: 1756926
• LaSalle County
Demographics & Population Profile
Population and demographics for Ottawa city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 18,684 | — | 2025 | Census |
| Median Age | 39.8 yrs | ±4.1 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 7,553 | ±344 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).