Some of the cities, towns, and places in Contra Costa County are Acalanes Ridge, Alamo, Alhambra Valley, Antioch, Bay Point, Bayview, Bayview-Montalvin, Bethel Island, Blackhawk, Brentwood, Byron, Camino Tassajara, Canyon, Castle Hill, Clayton, Clyde, Concord, Contra Costa Centre, Crockett, Danville, Diablo, Discovery Bay, East Richmond Heights, El Cerrito, El Sobrante, Hercules, Judsonville, Kensington, Knightsen, Lafayette, Livorna, Martinez, Montalvin Manor, Moraga, Mountain View, Norris Canyon, North Gate, North Richmond, Nortonville, Oakley, Orinda, Pacheco, Pinole, Pittsburg, Pleasant Hill, Point of Timber Landing, Port Chicago, Port Costa, Reliez Valley, Richmond, Rodeo, Rollingwood, Rossmoor, San Miguel, San Pablo, San Ramon, Saranap, Shell Ridge, Somersville, Stewartville, Tara Hills, Vine Hill, Walnut Creek, West Hartley
Contra Costa County is located in the state of California in the United States. As of the 2020 census, the population was 1,165,927. The county seat is Martinez. It occupies the northern portion of the East Bay region of the San Francisco Bay Area, and is primarily suburban. The county's name is Spanish for "opposite coast", referring to its position on the other side of the bay from San Francisco. Contra Costa County is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.