San Mateo County, California Citizen Voting-age Population By Race and Ethnicity in 2021 (ACS-5Yrs)

Updated on March 26, 2026.

Based on the US Census Bureau's special tabulation from the ACS 5-year estimates, in 2021, the citizen voting-age population for San Mateo County, CA was 504.89K. The Non-Hispanic White Alone ethnicity group had the highest citizen voting-age population (229.28K) and constituted 45.41% of the total.

The Non-Hispanic Asian Alone ethnicity group had the second highest citizen voting-age population (144.88K) and constituted 28.70% of the total. The Hispanic or Latino of All Races ethnicity group had the third highest (95.64K), constituting 18.94% of the total citizen voting-age population.

The charts and tables below shows the citizen voting-age population and percentages by race and ethnicity.

You can also see similar information for other California counties, and for California.

Data Source: US Census - ACS 5-Years (CVAP).

See this for other years:

San Mateo County, California Citizen Voting-age Population By Race and Ethnicity in 2021

Non-Hispanic White Alone

Non-Hispanic Asian Alone

Hispanic or Latino of All Races

Non-Hispanic Two Or More Races

Non-Hispanic Black Alone

Non-Hispanic Native Hawaiian & Pac. Islander Alone

Non-Hispanic American Indian & Alaska Native Alone

San Mateo County, California Citizen Voting-age Population By Race and Ethnicity in 2021

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Ethnicity	Voting-age Population	% of Voting-age Pop.
Non-Hispanic White Alone	229280	45.41
Non-Hispanic Asian Alone	144880	28.70
Hispanic or Latino of All Races	95635	18.94
Non-Hispanic Two Or More Races	14425	2.86
Non-Hispanic Black or African American Alone	13945	2.76
Non-Hispanic Native Hawaiian And Pacific Islander Alone	5940	1.18
Non-Hispanic American Indian and Alaska Native Alone	780	0.15