| Population | County | County Seat (Largest City) |
| 3,984,349 | |
| 2,412,827 | |
| 1,750,091 | |
| 1,622,899 | |
| 998,543 | |
| 762,010 | |
| 742,062 | |
| 726,604 | |
| 636,557 | |
| 532,141 | |
| 429,953 | |
| 394,193 | |
| 392,736 | |
| 322,077 | |
| 301,044 | |
| 288,239 | |
| 285,084 | |
| 264,418 | |
| 243,090 | |
| 236,941 | |
| | Population | County | County Seat (Largest City) |
| 230,213 | |
| 201,277 | |
| 175,122 | |
| 153,630 | |
| 149,476 | |
| 148,186 | |
| 131,941 | |
| 129,494 | |
| 127,321 | |
| 126,791 | |
| 120,918 | |
| 118,804 | |
| 117,528 | |
| 117,172 | |
| 114,546 | |
| 111,776 | |
| 109,635 | |
| 107,864 | |
| 100,527 | |
| 92,283 | |
|