Population, land area & population density (07-01-2008 est.) County Ref. Population Land mi² Land km² Pop. /mi² Pop. /km² Los Angeles County[15] 9,862,049 4,060.87 10,517.61 2,428.56 937.67 San Diego County[16] 3,095,313 4,199.89 10,877.67 714.56 275.89 Orange County[17] 3,010,759 789.40 2,044.54 3,813.98 1,472.59 Riverside County[18] 2,100,516 7,207.37 18,667.00 291.44 112.53 San Bernardino County[19] 2,015,355 20,052.50 51,935.74 100.50 38.80 Kern County[20] 800,458 8,140.96 21,084.99 98.32 37.96 Ventura County[21] 797,740 1,845.30 4,779.31 432.31 166.92 Santa Barbara County[22] 405,396 2,737.01 7,088.82 148.12 57.19 San Luis Obispo County[23] 265,297 3,304.32 8,558.15 80.29 31.00 Imperial County[24] 163,972 4,174.73 10,812.50 39.28 15.17 Southern California 22,422,614 56,512.35 146,366.31 396.77 153.19 California 36,756,666 155,959.34 403,932.84 235.68 91.00