Monticello city, Illinois
Official LSAD Designation: Monticello city • Census GEOID: 1750244
• Piatt County
Demographics & Population Profile
Population and demographics for Monticello city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 6,080 | — | 2025 | Census |
| Median Age | 43.8 yrs | ±5.3 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 2,675 | ±156 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).