RANKING · 2000 CENSUS · 58 SHOWN OF 58

Most densely populated, California counties · 2000

California counties ranked by residents per square mile (2023). This list covers the 58 counties in California that qualify, ranked against each other statewide.

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YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS 2000

01San Francisco County, CACA826,07916,632+0%

02Orange County, CACA3,149,5073,590+0%

03Los Angeles County, CACA9,694,9342,345+0%

04Alameda County, CACA1,636,6301,958+0%

05San Mateo County, CACA743,5681,576+0%

06Contra Costa County, CACA1,170,0701,324+0%

07Santa Clara County, CACA1,914,3911,303+0%

08Sacramento County, CACA1,618,4601,268+0%

09San Diego County, CACA3,282,248668+0%

10Santa Cruz County, CACA258,852574+0%

11Solano County, CACA455,376480+0%

12Marin County, CACA253,694475+0%

13Ventura County, CACA830,851409+0%

14San Joaquin County, CACA823,815405+0%

15Stanislaus County, CACA557,719299+0%

16Sonoma County, CACA486,444291+0%

17Riverside County, CACA2,544,916214+0%

18Placer County, CACA442,081177+0%

19Yolo County, CACA224,410166+0%

20Napa County, CACA132,949165+0%

21Santa Barbara County, CACA442,065146+0%

22Fresno County, CACA1,035,456134+0%

23Sutter County, CACA98,787131+0%

24Butte County, CACA209,211124+0%

25Monterey County, CACA433,729122+0%

26Merced County, CACA297,260109+0%

27Nevada County, CACA101,91196+0%

28Yuba County, CACA88,69195+0%

29Kings County, CACA154,32793+0%

30El Dorado County, CACA192,32392+0%

31San Bernardino County, CACA2,224,09185+0%

32Kern County, CACA927,06881+0%

33Tulare County, CACA485,14676+0%

34San Luis Obispo County, CACA282,36775+0%

35Amador County, CACA41,87659+0%

36Madera County, CACA167,92758+0%

37Lake County, CACA67,77246+0%

38Shasta County, CACA181,64843+0%

39Calaveras County, CACA46,60540+0%

40San Benito County, CACA70,08238+0%

41Humboldt County, CACA131,64735+0%

42Imperial County, CACA181,41134+0%

43Del Norte County, CACA26,41027+0%

44Mendocino County, CACA88,12225+0%

45Tuolumne County, CACA53,16025+0%

46Glenn County, CACA28,14120+0%

47Tehama County, CACA64,66519+0%

48Colusa County, CACA21,83616+0%

49Mariposa County, CACA16,91812+0%

50Plumas County, CACA18,5838+0%

51Lassen County, CACA28,1177+0%

52Siskiyou County, CACA42,0137+0%

53Mono County, CACA12,5054+0%

54Trinity County, CACA15,7204+0%

55Sierra County, CACA3,0984+0%

56Modoc County, CACA8,4262+0%

57Inyo County, CACA18,1582+0%

58Alpine County, CACA1,0432+0%

SHOWING 1–58 OF 58

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UPDATED 2026-06-02 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES