| County | Rank | Change (2020) ↓ | 2025 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Hancock County | 1 | 15.07% | 92,264 | 80,180 |
| Boone County | 2 | 12.1% | 79,742 | 71,137 |
| Hamilton County | 3 | 10.03% | 384,009 | 348,996 |
| Hendricks County | 4 | 9.87% | 192,923 | 175,596 |
| Johnson County | 5 | 6.07% | 172,085 | 162,237 |
| Clark County | 6 | 5.44% | 127,957 | 121,360 |
| Warrick County | 7 | 4.91% | 67,139 | 63,996 |
| Morgan County | 8 | 4.63% | 75,161 | 71,836 |
| Putnam County | 9 | 3.88% | 38,113 | 36,689 |
| DeKalb County | 10 | 3.87% | 44,968 | 43,292 |
| Allen County | 11 | 3.69% | 400,347 | 386,103 |
| Bartholomew County | 12 | 3.65% | 85,221 | 82,218 |
| Madison County | 13 | 3.52% | 134,746 | 130,167 |
| Parke County | 14 | 3.52% | 16,718 | 16,150 |
| Wells County | 15 | 3.25% | 29,069 | 28,155 |
| White County | 16 | 3.07% | 25,431 | 24,673 |
| Jasper County | 17 | 3.06% | 33,915 | 32,908 |
| Montgomery County | 18 | 3.02% | 39,081 | 37,935 |
| Switzerland County | 19 | 2.99% | 10,039 | 9,748 |
| Newton County | 20 | 2.92% | 14,202 | 13,799 |
| Fountain County | 21 | 2.8% | 16,953 | 16,492 |
| Rush County | 22 | 2.59% | 17,197 | 16,763 |
| Scott County | 23 | 2.44% | 24,971 | 24,377 |
| Martin County | 24 | 2.32% | 10,037 | 9,809 |
| Steuben County | 25 | 2.22% | 35,207 | 34,441 |
| Ripley County | 26 | 2.21% | 29,621 | 28,980 |
| Whitley County | 27 | 2.16% | 35,072 | 34,329 |
| Dearborn County | 28 | 2.16% | 51,845 | 50,750 |
| Greene County | 29 | 2.12% | 31,446 | 30,793 |
| Adams County | 30 | 1.99% | 36,562 | 35,849 |
| Brown County | 31 | 1.94% | 15,785 | 15,485 |
| Harrison County | 32 | 1.92% | 40,438 | 39,676 |
| Tippecanoe County | 33 | 1.89% | 189,902 | 186,387 |
| Daviess County | 34 | 1.86% | 33,976 | 33,357 |
| Warren County | 35 | 1.84% | 8,578 | 8,423 |
| Porter County | 36 | 1.73% | 176,309 | 173,318 |
| Benton County | 37 | 1.47% | 8,843 | 8,715 |
| Franklin County | 38 | 1.47% | 23,122 | 22,788 |
| Owen County | 39 | 1.43% | 21,622 | 21,318 |
| LaGrange County | 40 | 1.16% | 41,013 | 40,542 |
| Jennings County | 41 | 1.15% | 27,898 | 27,580 |
| Carroll County | 42 | 1.02% | 20,547 | 20,339 |
| Spencer County | 43 | 1% | 20,032 | 19,833 |
| Howard County | 44 | 0.97% | 84,401 | 83,589 |
| Jackson County | 45 | 0.95% | 46,920 | 46,479 |
| Floyd County | 46 | 0.83% | 81,185 | 80,519 |
| Delaware County | 47 | 0.78% | 112,637 | 111,762 |
| Noble County | 48 | 0.76% | 47,822 | 47,460 |
| Lake County | 49 | 0.71% | 502,480 | 498,957 |
| Jefferson County | 50 | 0.59% | 33,296 | 33,100 |
| Shelby County | 51 | 0.57% | 45,315 | 45,060 |
| Sullivan County | 52 | 0.56% | 20,929 | 20,812 |
| Knox County | 53 | 0.56% | 36,458 | 36,256 |
| Henry County | 54 | 0.52% | 49,157 | 48,903 |
| Clay County | 55 | 0.5% | 26,560 | 26,427 |
| Marshall County | 56 | 0.5% | 46,300 | 46,071 |
| St. Joseph County | 57 | 0.48% | 273,980 | 272,682 |
| Cass County | 58 | 0.37% | 37,924 | 37,786 |
| Perry County | 59 | 0.3% | 19,213 | 19,155 |
| Huntington County | 60 | 0.26% | 36,743 | 36,646 |
| Grant County | 61 | 0.16% | 66,614 | 66,507 |
| Vigo County | 62 | 0.16% | 106,295 | 106,130 |
| Washington County | 63 | 0.12% | 28,273 | 28,238 |
| Dubois County | 64 | 0.03% | 43,654 | 43,642 |
| Vanderburgh County | 65 | -0.02% | 180,304 | 180,336 |
| Vermillion County | 66 | -0.16% | 15,385 | 15,409 |
| Fayette County | 67 | -0.22% | 23,308 | 23,359 |
| Kosciusko County | 68 | -0.22% | 79,964 | 80,141 |
| Lawrence County | 69 | -0.5% | 44,790 | 45,016 |
| Monroe County | 70 | -0.57% | 138,784 | 139,585 |
| Fulton County | 71 | -0.64% | 20,338 | 20,469 |
| Orange County | 72 | -0.7% | 19,712 | 19,850 |
| Decatur County | 73 | -0.7% | 26,289 | 26,474 |
| LaPorte County | 74 | -0.71% | 111,474 | 112,270 |
| Elkhart County | 75 | -0.73% | 205,481 | 206,991 |
| Starke County | 76 | -0.79% | 23,212 | 23,396 |
| Wayne County | 77 | -0.84% | 65,949 | 66,507 |
| Marion County | 78 | -1% | 966,934 | 976,659 |
| Gibson County | 79 | -1.03% | 32,708 | 33,049 |
| Posey County | 80 | -1.04% | 24,924 | 25,185 |
| Union County | 81 | -1.37% | 6,985 | 7,082 |
| Clinton County | 82 | -1.59% | 32,652 | 33,178 |
| Pike County | 83 | -1.77% | 12,032 | 12,249 |
| Tipton County | 84 | -1.78% | 15,118 | 15,392 |
| Ohio County | 85 | -1.86% | 5,818 | 5,928 |
| Randolph County | 86 | -1.91% | 23,948 | 24,415 |
| Wabash County | 87 | -1.97% | 30,326 | 30,934 |
| Pulaski County | 88 | -2.06% | 12,257 | 12,515 |
| Blackford County | 89 | -2.18% | 11,841 | 12,105 |
| Miami County | 90 | -2.21% | 35,114 | 35,906 |
| Crawford County | 91 | -2.32% | 10,280 | 10,524 |
| Jay County | 92 | -3% | 19,860 | 20,474 |
Indiana's counties show varied growth patterns from 2020 to 2025. Hancock County leads with 15.07% annualized growth, followed by Boone County (12.1%) and Hamilton County (10.03%). The largest counties are Marion County (966,934), Lake County (502,480), and Allen County (400,347). Of the 92 counties in Indiana, 64 are growing while 28 have experienced population decline. Overall, counties averaged 1.39% annualized growth, with total population growing by 1.96% annually.