Alton city, Illinois
Official LSAD Designation: Alton city • Census GEOID: 1701114
• Madison County
Demographics & Population Profile
Population and demographics for Alton city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 25,013 | — | 2025 | Census |
| Median Age | 38 yrs | ±1.3 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 10,714 | ±390 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).