RANKING · 1990 CENSUS · 58 SHOWN OF 58

Most densely populated, California counties · 1990

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

Flip the list · Most sparsely populated, US counties →

CaliforniaAll states All rankings

SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest growing Fastest shrinking Most sparsely populated Best broadband access Worst broadband access

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS 2000

01San Francisco County, CACA826,07915,502−7%

02Orange County, CACA3,149,5073,040−15%

03Los Angeles County, CACA9,694,9342,183−7%

04Alameda County, CACA1,636,6301,735−11%

05San Mateo County, CACA743,5681,448−8%

06Santa Clara County, CACA1,914,3911,160−11%

07Contra Costa County, CACA1,170,0701,121−15%

08Sacramento County, CACA1,618,4601,079−15%

09San Diego County, CACA3,282,248593−11%

10Santa Cruz County, CACA258,852516−10%

11Marin County, CACA253,694442−7%

12Solano County, CACA455,376414−14%

13Ventura County, CACA830,851363−11%

14San Joaquin County, CACA823,815345−15%

15Stanislaus County, CACA557,719248−17%

16Sonoma County, CACA486,444246−15%

17Riverside County, CACA2,544,916162−24%

18Napa County, CACA132,949147−11%

19Yolo County, CACA224,410139−16%

20Santa Barbara County, CACA442,065135−7%

21Placer County, CACA442,081123−30%

22Fresno County, CACA1,035,456112−17%

23Butte County, CACA209,211111−10%

24Monterey County, CACA433,729108−11%

25Sutter County, CACA98,787107−18%

26Yuba County, CACA88,69192−3%

27Merced County, CACA297,26092−15%

28Nevada County, CACA101,91182−15%

29El Dorado County, CACA192,32374−19%

30Kings County, CACA154,32773−22%

31San Bernardino County, CACA2,224,09171−17%

32Kern County, CACA927,06867−18%

33San Luis Obispo County, CACA282,36766−12%

34Tulare County, CACA485,14665−15%

35Amador County, CACA41,87651−14%

36Madera County, CACA167,92741−28%

37Lake County, CACA67,77240−13%

38Shasta County, CACA181,64839−10%

39Humboldt County, CACA131,64733−6%

40Calaveras County, CACA46,60531−21%

41San Benito County, CACA70,08226−31%

42Imperial County, CACA181,41126−23%

43Del Norte County, CACA26,41023−15%

44Mendocino County, CACA88,12223−7%

45Tuolumne County, CACA53,16022−11%

46Glenn County, CACA28,14119−6%

47Tehama County, CACA64,66517−11%

48Colusa County, CACA21,83614−13%

49Mariposa County, CACA16,91810−17%

50Plumas County, CACA18,5838−5%

51Siskiyou County, CACA42,0137−2%

52Lassen County, CACA28,1176−18%

53Trinity County, CACA15,7204+0%

54Sierra County, CACA3,0983−7%

55Mono County, CACA12,5053−23%

56Modoc County, CACA8,4262+2%

57Inyo County, CACA18,1582+2%

58Alpine County, CACA1,0432−8%

SHOWING 1–58 OF 58

Download CSV (full list, 58 rows)

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