| County | Rank | Change (2020) ↓ | 2025 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Lincoln County | 1 | 18.31% | 77,666 | 65,648 |
| Lawrence County | 2 | 14.84% | 29,679 | 25,844 |
| Custer County | 3 | 11.69% | 9,309 | 8,335 |
| Pennington County | 4 | 8.7% | 119,097 | 109,566 |
| Minnehaha County | 5 | 7.79% | 213,100 | 197,695 |
| Brookings County | 6 | 7.61% | 36,958 | 34,343 |
| Turner County | 7 | 7.26% | 9,305 | 8,675 |
| Butte County | 8 | 6.96% | 11,009 | 10,293 |
| Hamlin County | 9 | 6.47% | 6,565 | 6,166 |
| Fall River County | 10 | 5.95% | 7,385 | 6,970 |
| Meade County | 11 | 5.21% | 31,458 | 29,899 |
| Sully County | 12 | 4.62% | 1,518 | 1,451 |
| Clay County | 13 | 4.61% | 15,691 | 15,000 |
| Stanley County | 14 | 4.17% | 3,095 | 2,971 |
| Moody County | 15 | 3.96% | 6,586 | 6,335 |
| McCook County | 16 | 3.9% | 5,891 | 5,670 |
| Codington County | 17 | 3.84% | 29,441 | 28,351 |
| Clark County | 18 | 3.76% | 3,998 | 3,853 |
| Douglas County | 19 | 3.74% | 2,940 | 2,834 |
| Faulk County | 20 | 3.61% | 2,209 | 2,132 |
| Union County | 21 | 3.34% | 17,423 | 16,860 |
| Beadle County | 22 | 3.3% | 19,797 | 19,165 |
| Aurora County | 23 | 3.18% | 2,822 | 2,735 |
| Marshall County | 24 | 3.16% | 4,444 | 4,308 |
| Sanborn County | 25 | 2.79% | 2,391 | 2,326 |
| Dewey County | 26 | 2.2% | 5,340 | 5,225 |
| Grant County | 27 | 1.98% | 7,687 | 7,538 |
| Yankton County | 28 | 1.89% | 23,727 | 23,286 |
| Lake County | 29 | 1.78% | 11,213 | 11,017 |
| Brule County | 30 | 1.72% | 5,331 | 5,241 |
| Tripp County | 31 | 1.68% | 5,705 | 5,611 |
| Perkins County | 32 | 1.48% | 2,884 | 2,842 |
| Bon Homme County | 33 | 1.39% | 7,067 | 6,970 |
| Kingsbury County | 34 | 1.37% | 5,270 | 5,199 |
| Gregory County | 35 | 1.32% | 4,056 | 4,003 |
| Deuel County | 36 | 1.05% | 4,340 | 4,295 |
| Edmunds County | 37 | 1.03% | 4,029 | 3,988 |
| Haakon County | 38 | 1.02% | 1,885 | 1,866 |
| Roberts County | 39 | 0.88% | 10,340 | 10,250 |
| Hutchinson County | 40 | 0.73% | 7,480 | 7,426 |
| Jerauld County | 41 | 0.49% | 1,656 | 1,648 |
| Buffalo County | 42 | 0.26% | 1,944 | 1,939 |
| Lyman County | 43 | 0.03% | 3,705 | 3,704 |
| Davison County | 44 | -0.02% | 19,952 | 19,956 |
| Hanson County | 45 | -0.23% | 3,455 | 3,463 |
| Day County | 46 | -0.75% | 5,403 | 5,444 |
| Harding County | 47 | -1.07% | 1,294 | 1,308 |
| Walworth County | 48 | -1.11% | 5,235 | 5,294 |
| Charles Mix County | 49 | -1.2% | 9,256 | 9,368 |
| Hughes County | 50 | -1.3% | 17,510 | 17,740 |
| Hand County | 51 | -1.37% | 3,097 | 3,140 |
| Miner County | 52 | -1.48% | 2,270 | 2,304 |
| Todd County | 53 | -2.06% | 9,131 | 9,323 |
| Brown County | 54 | -2.17% | 37,397 | 38,225 |
| Oglala Lakota County | 55 | -2.65% | 13,286 | 13,648 |
| Bennett County | 56 | -4.1% | 3,249 | 3,388 |
| Corson County | 57 | -4.7% | 3,712 | 3,895 |
| Spink County | 58 | -4.7% | 6,042 | 6,340 |
| Jackson County | 59 | -4.82% | 2,664 | 2,799 |
| Campbell County | 60 | -4.93% | 1,310 | 1,378 |
| Potter County | 61 | -5.1% | 2,347 | 2,473 |
| Mellette County | 62 | -5.89% | 1,807 | 1,920 |
| Hyde County | 63 | -7.2% | 1,160 | 1,250 |
| McPherson County | 64 | -7.99% | 2,210 | 2,402 |
| Ziebach County | 65 | -9.06% | 2,178 | 2,395 |
| Jones County | 66 | -11.99% | 815 | 926 |
South Dakota's counties show varied growth patterns from 2020 to 2025. Lincoln County leads with 18.31% annualized growth, followed by Lawrence County (14.84%) and Custer County (11.69%). The largest counties are Minnehaha County (213,100), Pennington County (119,097), and Lincoln County (77,666). Of the 66 counties in South Dakota, 43 are growing while 23 have experienced population decline. Overall, counties averaged 1.35% annualized growth, with total population growing by 5.67% annually.