San Francisco, officially the City and County of San Francisco, is the fourth-most populous city in California and the 17th-most populous in the United States, with a population of 827,526 in 2024. Among U.S. cities with a population of 300,000 or more, San Francisco is ranked first by per capita income, second by population density, and sixth by aggregate income as of 2023. Some 4.6 million residents live in the city's metropolitan statistical area, which is the 13th-largest in the United States. Around 9.2 million live in the San Jose–San Francisco–Oakland combined statistical area, the fifth-largest in the United States.
Prior to European settlement, San Francisco was inhabited by the Yelamu Ohlone.