The State of California is the third largest U.S. state by land area, sitting on 1155,858.33 square miles. The 58 counties in CA make up the land area.
So, apart from the tech economic hub of the U.S., the State of California also houses the largest county (County of San Bernardino) which sits on 20,062 sq mi. Its size is close to the size of West Virginia.
In the overall ranking, the State of California has more than 10 of its counties that make up the list of 100 largest Counties in the U.S. by land area and total land area.
They include San Bernardino County, Inyo County, Kern County, Riverside County, Siskiyou County, Fresno County, Tulare County, Los Angeles County, Lassen County, San Diego County, and Imperial County.
In that order, they are also the 10 biggest counties by land area in the State of California. Los Angeles County is also the second largest water area in CA.
San Bernardino County which top the list in this category is also the fifth largest California County by population, with 2,194,710 according to 2021 population estimates.
This post explores the land area (without waters) and the total area (overall territory including water area) of the 58 Counties in the State of California.
This list is based on the report by the United States Census Bureau during the 2000 Census. However, this ranking is based on land area, in another research, we shall compile the Counties that have the largest area covered by water.
Land Area of Counties in California
| Rank | County | Land Area (by sq mi) |
| 1 | San Bernardino | 20,068.01 sq mi |
| 2 | Inyo | 10,197.26 sq mi |
| 3 | Kern | 8,134.65 sq mi |
| 4 | Riverside | 7,209.27 sq mi |
| 5 | Siskiyou | 6,278.77 sq mi |
| 6 | Fresno | 5,958 sq mi |
| 7 | Tulare | 4,823.90 sq mi |
| 8 | Lassen | 4,541.34 sq mi |
| 9 | San Diego | 4,210.23 sq mi |
| 10 | Imperial | 4,175.54 sq mi |
| 11 | Los Angeles | 4,059.28 sq mi |
| 12 | Modoc | 3,948.23 sq mi |
| 13 | Shasta | 3,775.52 sq mi |
| 14 | Humboldt | 3,568.19 sq mi |
| 15 | Mendocino | 3,506.82 sq mi |
| 16 | San Luis Obispo | 3,300.85 sq mi |
| 17 | Monterey | 3,281.72 sq mi |
| 18 | Trinity | 3,179.27 sq mi |
| 19 | Mono | 3,048.90 sq mi |
| 20 | Tehama | 2,949.14 sq mi |
| 21 | Santa Barbara | 2,733.94 sq mi |
| 22 | Plumas | 2,553.06 sq mi |
| 23 | Tuolumne | 2,220.91 sq mi |
| 24 | Madera | 2,136.92 sq mi |
| 25 | Merced | 1,938 sq mi |
| 26 | Ventura | 1,840.79 sq mi |
| 27 | El Dorado | 1,707.85 sq mi |
| 28 | Butte | 1,636.49 sq mi |
| 29 | Sonoma | 1,575.63 sq mi |
| 30 | Stanislaus | 1,496.02 sq mi |
| 31 | Mariposa | 1,448.84 sq mi |
| 32 | Placer | 1,407.08 sq mi |
| 33 | San Joaquin | 1,392.37 sq mi |
| 34 | Kings | 1,390.97 sq mi |
| 35 | San Benito | 1,388.65 sq mi |
| 36 | Glenn | 1,313.97 sq mi |
| 37 | Santa Clara | 1,291.08 sq mi |
| 38 | Lake | 1,256.55 sq mi |
| 39 | Colusa | 1,150.71 sq mi |
| 40 | Calaveras | 1,020.02 sq mi |
| 41 | Yolo | 1,014.73 sq mi |
| 42 | Del Norte | 1,006.23 sq mi |
| 43 | Sacramento | 965.27 sq mi |
| 44 | Nevada | 957.76 sq mi |
| 45 | Sierra | 953.17 sq mi |
| 46 | Solano | 821.83 sq mi |
| 47 | Orange | 792.84 sq mi |
| 48 | Napa | 748.36 sq mi |
| 49 | Alameda | 737.46 sq mi |
| 50 | Alpine | 738.34 sq mi |
| 51 | Contra Costa | 716.93 sq mi |
| 52 | Yuba | 632.01 sq mi |
| 53 | Sutter | 602.70 sq mi |
| 54 | Amador | 594.58 sq mi |
| 55 | Marin | 520.42 sq mi |
| 56 | San Mateo | 448.62 sq mi |
| 57 | Santa Cruz | 445.11 sq mi |
| 58 | San Francisco | 46.91 sq mi |
Recap:
Ranking the land area of counties in the State of California, San Francisco County (home of tech hub), is the smallest in CA; Santa Cruz County is the second smallest followed by San Mateo while Marin, and Amador occupy the fourth and fifth position respectively.
The 58 Counties make up the 155,858.33 sq mi land area of the State of California.