| County | 1999 population |
|---|
| Marion | 810946 |
| Lake | 480619 |
| Allen | 316471 |
| St. Joseph | 258537 |
| Elkhart | 174680 |
| Hamilton | 172094 |
| Vanderburgh | 167922 |
| Porter | 147758 |
| Tippecanoe | 142475 |
| Madison | 130990 |
| Monroe | 116923 |
| Delaware | 115472 |
| Johnson | 112724 |
| La Porte | 109939 |
| Vigo | 104349 |
| Hendricks | 98826 |
| Clark | 95121 |
| Howard | 83736 |
| Floyd | 72243 |
| Grant | 72082 |
| Kosciusko | 71336 |
| Wayne | 71134 |
| Bartholomew | 69714 |
| Morgan | 67003 |
| Hancock | 55617 |
| Warrick | 52557 |
| Henry | 48377 |
| Dearborn | 48011 |
| Marshall | 46129 |
| Lawrence | 45752 |
| Boone | 44835 |
| Shelby | 43630 |
| Noble | 43241 |
| Jackson | 41319 |
| Dubois | 40093 |
| De Kalb | 39683 |
| Knox | 39051 |
| Cass | 38964 |
| Huntington | 37377 |
| Montgomery | 36583 |
| Harrison | 35376 |
| Putnam | 34788 |
| Wabash | 34538 |
| Lagrange | 33997 |
| Miami | 33605 |
| Adams | 33168 |
|
| County | 1999 population |
|---|
| Greene | 33158 |
| Clinton | 32964 |
| Gibson | 32230 |
| Jefferson | 31813 |
| Steuben | 31742 |
| Whitley | 30811 |
| Jasper | 29462 |
| Daviess | 29084 |
| Washington | 28233 |
| Jennings | 28106 |
| Ripley | 27660 |
| Randolph | 27417 |
| Clay | 26903 |
| Wells | 26810 |
| Posey | 26292 |
| Fayette | 25860 |
| Decatur | 25704 |
| White | 25522 |
| Starke | 23597 |
| Scott | 23433 |
| Franklin | 22120 |
| Jay | 21686 |
| Sullivan | 21535 |
| Spencer | 21178 |
| Fulton | 20893 |
| Owen | 20619 |
| Carroll | 20004 |
| Orange | 19835 |
| Perry | 19091 |
| Fountain | 18374 |
| Rush | 18208 |
| Vermillion | 16954 |
| Parke | 16908 |
| Tipton | 16641 |
| Brown | 15992 |
| Newton | 14844 |
| Blackford | 13927 |
| Pulaski | 13527 |
| Pike | 13021 |
| Crawford | 10739 |
| Martin | 10379 |
| Benton | 9776 |
| Switzerland | 8961 |
| Warren | 8349 |
| Union | 7297 |
| Ohio | 5457 |
|
