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 i…