Ranking of California Counties By Population in 2018

Updated on January 28, 2024.

Based on the US Census Vintage data estimates, in 2018, the Population for California was 39.44M. Among all California counties, Los Angeles County had the highest population (10.06M), followed by San Diego County (3.33M), and Orange County (3.18M).

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 2018
Los Angeles
10.06M
San Diego
3.33M
Orange
3.18M
Riverside
2.44M
San Bernardino
2.17M
Santa Clara
1.93M
Alameda
1.67M
Sacramento
1.54M
Contra Costa
1.15M
Fresno
991.30K
Ranking of California Counties By Population in 2018
Rank
County
Population
1 Los Angeles County 10,061,533
2 San Diego County 3,332,483
3 Orange County 3,175,579
4 Riverside County 2,443,221
5 San Bernardino County 2,165,627
6 Santa Clara County 1,931,985
7 Alameda County 1,666,596
8 Sacramento County 1,539,550
9 Contra Costa County 1,150,840
10 Fresno County 991,298
11 Kern County 893,618
12 San Francisco County 879,676
13 Ventura County 847,222
14 San Mateo County 768,410
15 San Joaquin County 752,590
16 Stanislaus County 547,855
17 Sonoma County 497,221
18 Tulare County 464,279
19 Solano County 445,931
20 Santa Barbara County 445,137
21 Monterey County 433,359
22 Placer County 392,735
23 San Luis Obispo County 283,250
24 Merced County 273,733
25 Santa Cruz County 273,713
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