There are 26 cities in Alameda County, California.
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 Population | 2020 Population | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| San Francisco | 1 | 788,478 | 870,518 | -2.54% | 16,884 | 46.7 | City |
| Oakland | 2 | 435,024 | 440,943 | -0.34% | 7,773 | 56.0 | City |
| Fremont | 3 | 224,800 | 230,430 | -0.62% | 2,878 | 78.1 | City |
| Hayward | 4 | 153,344 | 162,666 | -1.5% | 3,347 | 45.8 | City |
| Berkeley | 5 | 117,214 | 124,205 | -1.47% | 11,236 | 10.4 | City |
| Tracy | 6 | 99,473 | 93,620 | 1.49% | 3,777 | 26.3 | City |
| San Leandro | 7 | 84,137 | 90,724 | -1.92% | 6,315 | 13.3 | City |
| Livermore | 8 | 81,252 | 87,875 | -2% | 3,058 | 26.6 | City |
| Alameda | 9 | 74,434 | 78,109 | -1.22% | 7,158 | 10.4 | City |
| Pleasanton | 10 | 72,982 | 79,665 | -2.24% | 3,023 | 24.1 | City |
| Dublin | 11 | 68,067 | 72,311 | -1.54% | 4,470 | 15.2 | City |
| Castro Valley | 12 | 66,120 | 64,392 | 0.51% | 3,925 | 16.8 | CDP |
| Union City | 13 | 63,909 | 69,927 | -2.3% | 3,295 | 19.4 | City |
| Newark | 14 | 46,733 | 47,517 | -0.42% | 3,357 | 13.9 | City |
| San Lorenzo | 15 | 30,810 | 30,117 | 1.73% | 10,115 | 3.0 | CDP |
| Mountain House | 16 | 25,909 | 21,387 | 4.68% | 5,684 | 4.6 | CDP |
| Ashland | 17 | 23,370 | 23,566 | 0.44% | 12,680 | 1.8 | CDP |
| Albany | 18 | 18,721 | 20,225 | -1.97% | 10,459 | 1.8 | City |
| Discovery Bay | 19 | 15,697 | 15,904 | 1.07% | 2,807 | 5.6 | CDP |
| Cherryland | 20 | 15,628 | 15,976 | 0.42% | 13,100 | 1.2 | CDP |
| Emeryville | 21 | 12,670 | 12,918 | -0.49% | 9,953 | 1.3 | City |
| Fairview | 22 | 10,680 | 10,834 | 0.46% | 3,591 | 3.0 | CDP |
| Piedmont | 23 | 10,427 | 11,258 | -1.96% | 6,134 | 1.7 | City |
| Kensington | 24 | 5,348 | 5,171 | 0.38% | 5,548 | 1.0 | CDP |
| Byron | 25 | 2,025 | 2,057 | 2.74% | 311 | 6.5 | CDP |
| Sunol | 26 | 921 | 835 | 0% | 33 | 28.3 | 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 Francisco is the largest city in Alameda County.
Sunol is the smallest city in Alameda County.
There are 26 cities in Alameda County, California.