Contra Costa County, California

Contra Costa County profile, demographic data, and geographic information.

Local Government & Public Administration

Authoritative general-purpose local government units serving this area U.S. Census Bureau GUS (2026) / GMAF

Government Unit	Unit Type	Jurisdiction Role	Contact / Address
COUNTY OF CONTRA COSTA GUS Population: 1,172,607 (2024) ID: 161097	County	Official County Government	Contact: CHAIRMAN 651 PINE ST, RM 108A, MARTINEZ CA 94553-1229
CITY OF CONCORD GUS Population: 124,016 (2024) ID: 161132	Municipal	Municipal Government Within County	Contact: MAYOR 1950 PARKSIDE DR, CONCORD CA 94519-2578
CITY OF ANTIOCH GUS Population: 118,453 (2024) ID: 123096	Municipal	Municipal Government Within County	Contact: FINANCE DIRECTOR PO BOX 5007, ANTIOCH CA 94531-5007
CITY OF RICHMOND GUS Population: 115,353 (2024) ID: 161135	Municipal	Municipal Government Within County	Contact: CITY MANAGER 450 CIVIC CENTER PLAZA, RICHMOND CA 94804-1661
CITY OF SAN RAMON GUS Population: 85,924 (2024) ID: 161138	Municipal	Municipal Government Within County	Contact: ADMINSTRATIVE SERVICES DIRECTOR 7000 BOLLINGER CANYON ROAD, SAN RAMON CA 94583
CITY OF PITTSBURG GUS Population: 77,131 (2024) ID: 123098	Municipal	Municipal Government Within County	Contact: CITY CLERK 65 CIVIC AVE, PITTSBURG CA 94565-3814
CITY OF WALNUT CREEK GUS Population: 70,817 (2024) ID: 183821	Municipal	Municipal Government Within County	Contact: DEPUTY CITY CLERK 1666 N MAIN ST, WALNUT CREEK CA 94596-4661
CITY OF BRENTWOOD GUS Population: 66,286 (2024) ID: 207580	Municipal	Municipal Government Within County	Contact: ASSITANT PLANNER 150 CITY PARK WAY, BRENTWOOD CA 94513
CITY OF OAKLEY GUS Population: 47,158 (2024) ID: 196025	Municipal	Municipal Government Within County	Contact: CITY MANAGER 3231 MAIN ST, OAKLEY CA 94561-3147
TOWN OF DANVILLE GUS Population: 43,410 (2024) ID: 161137	Municipal	Municipal Government Within County	Contact: ASSISTANT TO THE TOWN MANAGER 510 LA GONDA WAY, DANVILLE CA 94526-1722
CITY OF MARTINEZ GUS Population: 37,006 (2024) ID: 161133	Municipal	Municipal Government Within County	Contact: CITY MANAGER 525 HENRIETTA STREET, MARTINEZ CA 94553-2394
CITY OF PLEASANT HILL GUS Population: 34,169 (2024) ID: 161139	Municipal	Municipal Government Within County	Contact: MAYOR 100 GREGORY LN, PLEASANT HILL CA 94523-3381
CITY OF SAN PABLO GUS Population: 31,562 (2024) ID: 161136	Municipal	Municipal Government Within County	Contact: DEVELOPMENT SERVICES MANAGER 13831 SAN PABLO AVE, #3, SAN PABLO CA 94806-3703
CITY OF HERCULES GUS Population: 26,499 (2024) ID: 123097	Municipal	Municipal Government Within County	Contact: CITY CLERK 111 CIVIC DR, HERCULES CA 94547-1771
CITY OF EL CERRITO GUS Population: 26,409 (2024) ID: 100656	Municipal	Municipal Government Within County	Contact: FINANCE DIRECTOR /TREASURER 10890 SAN PABLO AVE, EL CERRITO CA 94530
CITY OF LAFAYETTE GUS Population: 25,371 (2024) ID: 193104	Municipal	Municipal Government Within County	Contact: CITY MANAGER 3675 MT DIABLO BLVD, STE 210, LAFAYETTE CA 94549-3793
CITY OF ORINDA GUS Population: 19,573 (2024) ID: 123099	Municipal	Municipal Government Within County	Contact: CITY CLERK 22 ORINDA WAY, ORINDA CA 94563-2519
CITY OF PINOLE GUS Population: 18,663 (2024) ID: 161134	Municipal	Municipal Government Within County	Contact: PLANNING MANAGER 2131 PEAR ST, PINOLE CA 94564-1797
TOWN OF MORAGA GUS Population: 16,698 (2024) ID: 100661	Municipal	Municipal Government Within County	Contact: ADMINISTRATIVE SERVICES DIRECTOR 329 RHEEM BLVD, STE 1, MORAGA CA 94556-3108
CITY OF CLAYTON GUS Population: 10,933 (2024) ID: 183822	Municipal	Municipal Government Within County	Contact: CITY CLERK/ HR 6000 HERITAGE TRL, CLAYTON CA 94517-1250