Contra Costa County

Blue outline of the State of California with a red outline showing Contra Costa county.
  • Population: 1,160,000
  • Registered voters: 700,000
  • Local election authority: County Clerk Recorder – Registrar of Voters (elected)
  • Full-time Election Staff: 28.5
  • Contra Costa County Election Website

Contra Costa County is a county located in the northern portion of the East Bay region of the San Francisco Bay Area of Northern California. The county seat is Martinez, but the largest city is Concord. Other major cities include Richmond, Antioch, Walnut Creek, Brentwood, and San Ramon.

Contra Costa County is known for its diverse communities, thriving economy, and abundant recreational opportunities. It is home to a number of regional parks, a historic site, and open spaces, including Mount Diablo State Park, Briones Regional Park, the John Muir National Historic Site and the Iron Horse Regional Trail. 

The county also has a robust transportation network, with several major highways and interstates, as well as access to public transportation systems like BART and AC Transit.

The county has a strong economy, with major industries including healthcare, education, and technology. Some of the largest employers in Contra Costa County include Kaiser Permanente, Chevron, and the Mount Diablo Unified School District.

Contra Costa was recently awarded the 2022 Clearie Honorable Mention for Outstanding Election Official State Association Program or Local Office by the U.S. Election Assistance Commission.