Contra Costa County, CA ZIP Codes & Directory
Complete postal guide for Contra Costa County, California. Featuring the official county seat of Martinez, largest municipality Concord, and serving 25 incorporated municipal entities.
Municipalities Located in Contra Costa County
Incorporated Cities, Towns, and Villages
Alamo
cityZIPs: 94507
Antioch
cityZIPs: 94509, 94531
Brentwood
cityZIPs: 94513
Byron
cityZIPs: 94514
Clayton
cityZIPs: 94517
Concord
cityZIPs: 94518, 94519 , +2 more
Crockett
cityZIPs: 94525
Danville
cityZIPs: 94506, 94526
Discovery Bay
cityZIPs: 94505
El Cerrito
cityZIPs: 94530
El Sobrante
cityZIPs: 94803
Hercules
cityZIPs: 94547
Lafayette
cityZIPs: 94549
Martinez
cityZIPs: 94553
Moraga
cityZIPs: 94556, 94575
Oakley
cityZIPs: 94561
Orinda
cityZIPs: 94563
Pinole
cityZIPs: 94564
Pittsburg
cityZIPs: 94565
Pleasant Hill
cityZIPs: 94523
Richmond
cityZIPs: 94801, 94804 , +2 more
Rodeo
cityZIPs: 94572
San Pablo
cityZIPs: 94806
San Ramon
cityZIPs: 94582, 94583
Walnut Creek
cityZIPs: 94595, 94596 , +2 more
Active USPS ZIP Codes in Contra Costa County
Standard delivery zones and geographic service boundaries
Frequently Asked Questions About Contra Costa County, CA
What is the county seat and largest city in Contra Costa County? ▾
The official county seat of Contra Costa County is Martinez, and its largest incorporated municipality by population is Concord.
How many cities, towns, and villages are in Contra Costa County? ▾
Contra Costa County encompasses 25 incorporated municipal entities, including 25 cities, 0 towns, and 0 villages.
What is the total population and land area of Contra Costa County? ▾
According to official U.S. Census Bureau data, Contra Costa County has a population of approximately 1,165,927 residents and spans an area of 716 square miles.
How many ZIP codes operate in Contra Costa County? ▾
There are 38 active USPS ZIP codes serving addresses within Contra Costa County, California.