San Ramon is a city in Contra Costa County, California, United States, located within the San Ramon Valley, and 34 miles east of San Francisco. San Ramon's population was 84,605 per the 2020 census, making it the 4th largest city in Contra Costa County, behind Richmond, Concord and Antioch. San Ramon is home to the headquarters of Chevron Corporation, Cooper Companies, the West Coast headquarters of AT&T, GE Digital, as well as the San Ramon Medical Center.