Arnold city, Missouri
Official LSAD Designation: Arnold city • Census GEOID: 2901972
• Jefferson County
Demographics & Population Profile
Population and demographics for Arnold city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 20,994 | — | 2025 | Census |
| Median Age | 39.7 yrs | ±2.5 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 8,394 | ±341 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).