Monmouth city, Oregon
Official LSAD Designation: Monmouth city • Census GEOID: 4149550
• Polk County
Demographics & Population Profile
Population and demographics for Monmouth city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 11,543 | — | 2025 | Census |
| Median Age | 27.1 yrs | ±1.8 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 3,621 | ±274 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).