| Area | 821 square miles (2,125 km2) |
| Type | County |
| Economy | Advanced technology manufacturing • Agriculture • Aerospace • Environmental research • Sustainable development |
| Location | Californian Republic, North America |
| Named for | Alameda Creek |
| Population | 1,613,519 (2020) |
| County seat | |
| Incorporated | March 25, 1853 |
| Major cities | |
| Major landmarks | Alameda County Courthouse • USS Hornet Museum • Lake Merritt • Fremont Central Park |
| Population density | 1,964/sq mi (758/km2) |
