Oakland, California is a city.
Oakland [ ˈoʊklənd ] is the largest city and the county seat of Alameda County , California , United States . A major West Coast port city , Oakland is the largest city in the East Bay region of the San Francisco Bay Area , the third largest city overall in the San Francisco Bay Area , the eighth largest city in California , and the 45th largest city in the United States , with a population of 419,267 . In addition , due to a steady influx of immigrants during the 20th century , along with thousands of African-American war-industry workers who relocated from the Deep South during the 1940s , Oakland is the most ethnically diverse major city in the country .