PlainCities

Counties · California

Counties of California

California has 58 counties. Los Angeles County is the largest with 9,694,934 residents in 2025. 22 of the 58 gained residents between 2020 and 2025 by the Census Bureau's estimates.

What counties are in California?

Sorted by the 2025 population estimate; sort by any column.

Counties of California: 2025 estimate, change since 2020, ACS 2020-2024 5-year estimates
Los Angeles County9,694,934−3.2%1422,498$90,112$834,200
San Diego County3,282,248−0.5%57737$106,268$854,700
Orange County3,149,507−1.2%45614$116,289$962,600
Riverside County2,544,916+5.2%75518$93,074$557,300
San Bernardino County2,224,091+1.9%52466$85,478$505,000
Santa Clara County1,914,391−1.1%24408$164,281$1,490,600
Alameda County1,636,630−2.7%20379$129,367$1,090,100
Sacramento County1,618,460+2.1%35363$92,175$534,200
Contra Costa County1,170,070+0.3%53242$127,229$866,800
Fresno County1,035,456+2.7%45225$74,201$388,800
Kern County927,068+2.0%88236$70,210$338,300
Ventura County830,851−1.6%24190$109,797$822,700
San Francisco County826,079−6.0%1244$140,970$1,394,500
San Joaquin County823,815+5.7%28174$92,179$530,700
San Mateo County743,568−2.7%33174$158,855$1,559,600
Stanislaus County557,719+0.8%33112$81,468$450,100
Sonoma County486,444−0.5%38122$104,674$815,500
Tulare County485,146+2.5%70103$71,300$330,100
Solano County455,376+0.4%11100$100,401$617,700
Placer County442,081+9.2%2392$115,998$688,100
Santa Barbara County442,065−1.4%28109$98,161$790,700
Monterey County433,729−1.7%30104$97,230$781,000
Merced County297,260+5.2%2563$65,510$391,800
San Luis Obispo County282,367−0.0%3070$97,446$824,700
Santa Cruz County258,852−4.9%3070$111,093$1,027,500
Marin County253,694−3.3%3163$149,091$1,507,300
Yolo County224,410+3.0%1753$91,752$620,700
Butte County209,211−1.1%3054$67,928$424,700
El Dorado County192,323+0.6%1555$108,845$679,900
Shasta County181,648−0.4%3250$72,636$366,400
Imperial County181,411+0.9%1840$57,681$309,600
Madera County167,927+7.5%1734$76,627$393,200
Kings County154,327+1.2%1131$70,995$324,300
Napa County132,949−3.7%1140$111,471$869,500
Humboldt County131,647−3.5%4036$61,160$446,900
Nevada County101,911−0.3%1426$89,882$621,800
Sutter County98,787−0.8%921$79,704$433,500
Yuba County88,691+8.7%1119$76,373$412,300
Mendocino County88,122−3.8%2324$68,092$512,200
San Benito County70,082+9.2%512$114,394$793,400
Lake County67,772−0.6%1521$60,621$324,300
Tehama County64,665−1.9%1814$63,784$339,600
Tuolumne County53,160−4.4%1918$77,404$433,200
Calaveras County46,605+2.9%2314$78,647$457,200
Siskiyou County42,013−4.7%2116$59,095$309,500
Amador County41,876+3.4%2010$88,044$449,800
Glenn County28,141−2.7%58$67,139$352,400
Lassen County28,117−14.1%169$67,403$265,300
Del Norte County26,410−4.8%79$67,058$342,000
Colusa County21,836+0.0%96$75,672$393,400
Plumas County18,583−6.1%467$66,031$360,200
Inyo County18,158−4.5%216$73,991$348,700
Mariposa County16,918−1.3%176$68,412$387,900
Trinity County15,720−2.5%144$53,002$325,800
Mono County12,505−5.3%184$99,415$639,400
Modoc County8,426−3.2%134$59,455$224,700
Sierra County3,098−4.1%111$63,355$331,900
Alpine County1,043−11.5%51$105,521$590,200

Source: PEP Vintage 2025 (CO-EST2025); American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Census population estimates

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections