Ranking of California Counties By Population in 2021

Updated on August 1, 2024.

Based on the US Census Vintage data estimates, in 2021, the Population for California was 39.15M. Among all California counties, Los Angeles County had the highest population (9.81M), followed by San Diego County (3.27M), and Orange County (3.16M).

The chart below shows the top 10 counties, and the table below shows the ranking of all California counties.

You can see similar ranking information for related topics, and for other states. You can also see the ranking of all counties in the United States.

See this for other years:
Ranking of California Counties By Population in 2021
Los Angeles
9.81M
San Diego
3.27M
Orange
3.16M
Riverside
2.45M
San Bernardino
2.19M
Santa Clara
1.89M
Alameda
1.64M
Sacramento
1.59M
Contra Costa
1.16M
Fresno
1.01M
Ranking of California Counties By Population in 2021
Rank
County
Population
1 Los Angeles County 9,809,462
2 San Diego County 3,274,432
3 Orange County 3,160,611
4 Riverside County 2,453,399
5 San Bernardino County 2,193,087
6 Santa Clara County 1,885,173
7 Alameda County 1,644,047
8 Sacramento County 1,588,810
9 Contra Costa County 1,163,941
10 Fresno County 1,013,103
11 Kern County 912,709
12 Ventura County 839,471
13 San Francisco County 811,935
14 San Joaquin County 788,354
15 San Mateo County 739,149
16 Stanislaus County 552,723
17 Sonoma County 484,519
18 Tulare County 477,176
19 Solano County 450,653
20 Santa Barbara County 437,521
21 Monterey County 437,158
22 Placer County 413,047
23 Merced County 284,610
24 San Luis Obispo County 279,464
25 Santa Cruz County 260,475
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