| Los Angeles County, California | 10,014,000 |
| Cook County, Illinois | 5,275,540 |
| Harris County, Texas | 4,731,140 |
| Maricopa County, Arizona | 4,420,570 |
| San Diego County, California | 3,298,630 |
| Orange County, California | 3,186,990 |
| Kings County, New York | 2,736,070 |
| Miami-Dade County, Florida | 2,701,770 |
| Dallas County, Texas | 2,613,540 |
| Riverside County, California | 2,418,180 |
| Queens County, New York | 2,405,460 |
| King County, Washington | 2,269,680 |
| Clark County, Nevada | 2,265,460 |
| San Bernardino County, California | 2,181,650 |
| Tarrant County, Texas | 2,110,640 |
| Bexar County, Texas | 2,009,320 |
| Broward County, Florida | 1,944,380 |
| Santa Clara County, California | 1,936,260 |
| Wayne County, Michigan | 1,793,560 |
| New York County, New York | 1,694,250 |
| Alameda County, California | 1,682,350 |
| Middlesex County, Massachusetts | 1,632,000 |
| Philadelphia County, Pennsylvania | 1,603,800 |
| Sacramento County, California | 1,585,060 |
| Suffolk County, New York | 1,525,920 |