Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| San Mateo | 1 | 99,884 | 105,656 | -1.42% | 8,232 | 12.1 | City |
| Daly City | 2 | 98,158 | 104,858 | -1.68% | 12,851 | 7.6 | City |
| Redwood City | 3 | 80,032 | 83,887 | -1.19% | 4,139 | 19.3 | City |
| South San Francisco | 4 | 62,196 | 65,902 | -1.47% | 6,757 | 9.2 | City |
| San Bruno | 5 | 40,520 | 43,746 | -1.95% | 7,382 | 5.5 | City |
| Pacifica | 6 | 35,730 | 38,514 | -1.91% | 2,840 | 12.6 | City |
| Foster City | 7 | 31,662 | 33,733 | -1.61% | 8,361 | 3.8 | City |
| Menlo Park | 8 | 31,023 | 33,690 | -2.1% | 3,105 | 10.0 | City |
| Burlingame | 9 | 29,454 | 31,278 | -1.52% | 6,705 | 4.4 | City |
| San Carlos | 10 | 28,270 | 30,638 | -2.05% | 5,224 | 5.4 | City |
| East Palo Alto | 11 | 27,638 | 29,948 | -2.05% | 10,933 | 2.5 | City |
| Belmont | 12 | 26,076 | 28,258 | -2.05% | 5,632 | 4.6 | City |
| Millbrae | 13 | 21,736 | 23,138 | -1.59% | 6,649 | 3.3 | City |
| North Fair Oaks | 14 | 13,556 | 14,992 | -0.59% | 11,334 | 1.2 | CDP |
| Half Moon Bay | 15 | 10,883 | 11,771 | -2% | 1,744 | 6.2 | City |
| Hillsborough | 16 | 10,723 | 11,363 | -1.47% | 1,739 | 6.2 | Town |
| Atherton | 17 | 6,707 | 7,171 | -1.7% | 1,337 | 5.0 | Town |
| El Granada | 18 | 5,682 | 6,069 | 0.28% | 1,157 | 4.9 | CDP |
| Woodside | 19 | 4,952 | 5,291 | -1.69% | 432 | 11.5 | Town |
| Brisbane | 20 | 4,489 | 4,840 | -1.92% | 1,504 | 3.0 | City |
| Broadmoor | 21 | 4,460 | 4,140 | 0.47% | 10,324 | 0.4 | CDP |
| Emerald Lake Hills | 22 | 4,450 | 4,893 | 0.29% | 3,765 | 1.2 | CDP |
| Portola Valley | 23 | 4,123 | 4,447 | -1.93% | 454 | 9.1 | Town |
| West Menlo Park | 24 | 3,358 | 3,720 | -0.65% | 6,924 | 0.5 | CDP |
| Highlands | 25 | 3,185 | 2,985 | 7.67% | 2,450 | 1.3 | CDP |
| Moss Beach | 26 | 3,175 | 3,436 | 0.16% | 1,419 | 2.2 | CDP |
| Montara | 27 | 2,606 | 2,833 | -0.8% | 672 | 3.9 | CDP |
| Baywood Park | 28 | 1,968 | 1,786 | 7.66% | 3,598 | 0.5 | CDP |
| La Honda | 29 | 1,504 | 1,229 | 2.8% | 353 | 4.3 | CDP |
| Ladera | 30 | 1,427 | 1,385 | 0% | 3,319 | 0.4 | CDP |
| Colma | 31 | 1,376 | 1,498 | -2.2% | 728 | 1.9 | Town |
| Pescadero | 32 | 300 | 418 | -7.41% | 75 | 4.0 | CDP |
| Loma Mar | 33 | 112 | 282 | 0% | 65 | 1.7 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
San Mateo is the largest city in San Mateo County.
Loma Mar is the smallest city in San Mateo County.
There are 33 cities in San Mateo County, California.