Marin County's 2026 population is estimated at 257,788, reflecting a 0.27% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Marin County is the 26th largest county in California. The 2010 population was 252,906 and has grown 1.93% since 2010.
Data after 2023 is projected based on recent change
Overall: 47.4 years
Female: 49 years
Male: 45.9 years
There are 207,983 adults, (61,345 of whom are seniors) in Marin County.
Female: 131,092 (50.8%)
Male: 126,877 (49.2%)
The racial composition of Marin County includes 67.69% White, 10.7% other race, 6.21% Asian, and smaller percentages for Black or African American, Native American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 174,615 | 67.69% |
| Two or more races | 31,742 | 12.3% |
| Other race | 27,605 | 10.7% |
| Asian | 16,031 | 6.21% |
| Black or African American | 5,670 | 2.2% |
| Native American | 1,871 | 0.73% |
| Native Hawaiian or Pacific Islander | 435 | 0.17% |
Marin County 's average per capita income is $83,637. Household income levels show a median of $149,091. The poverty rate stands at 8.31%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $230,954 | $324,790 |
| Families | $199,115 | $288,173 |
| Households | $149,091 | $232,566 |
| Non Families | $81,671 | $126,871 |
Average Income
Median Household Income
Poverty Rate