Chula Vista is a city in San Diego County, California, United States. It is the second-most populous city in the San Diego metropolitan area, the seventh-most populous city in Southern California, the 15th-most populous city in the state of California, and the 81st-most populous city in the United States. The population was 275,487 as of the 2020 census, up from 243,916 as of the 2010 census. It is located in the South Bay, about halfway—7.5 miles (12.1 km)—between the two downtowns of the San Diego–Tijuana region. Chula Vista is named for its scenic location between San Diego Bay and coastal mountain foothills.