Contra Costa County Flag

Contra Costa County

State:
California
County Seat:
Martinez

Contra Costa County's estimated 2025 population is 1,183,035 with a growth rate of 0.89% in the past year according to the most recent United States census data. Contra Costa County is the 9th largest county in California. The 2010 population was 1,052,516 and has seen a growth of 12.4% since that time.

1,183,035
Total Population
1,650
Population Density (mi²)
9
Population Rank (State)
10.4K 0.89%
Annual Population Growth

Contra Costa County Population

Demographics

Economics and Income Statistics

Sources

  1. City and Town Population Totals: 2020-2024
  2. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  3. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  4. American Community Survey (2009 - 2013)
  5. Census QuickFacts
  6. Historical Populations of States and Counties (1790 - 1990)