San Mateo city, California
Official LSAD Designation: San Mateo city • Census GEOID: 0668252
• San Mateo County
Demographics & Population Profile
Population and demographics for San Mateo city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 103,337 | — | 2025 | Census |
| Median Age | 38.3 yrs | ±0.7 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 39,895 | ±820 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).