54 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Aberdeen | 1 | 27,789 | 28,437 | -0.47% | 1,682 | 17 | City |
| Groton | 2 | 1,333 | 1,381 | -0.74% | 761 | 2 | City |
| Lincoln | 3 | 1,153 | 1,160 | -0.09% | 24 | 48 | Township |
| Aberdeen | 4 | 880 | 901 | -0.11% | 23 | 38 | Township |
| Bath | 5 | 684 | 698 | -0.29% | 16 | 42 | Township |
| Warner | 6 | 508 | 523 | -0.59% | 6 | 80 | Township |
| Warner | 7 | 444 | 473 | -1.33% | 1,591 | 0 | Town |
| Ravinia | 8 | 370 | 377 | 0% | 11 | 35 | Township |
| Prairiewood | 9 | 295 | 301 | 0% | 500 | 1 | Township |
| Ordway | 10 | 278 | 287 | -0.71% | 7 | 41 | Township |
| Frederick | 11 | 207 | 214 | -0.96% | 153 | 1 | Town |
| Gem | 12 | 191 | 195 | -0.52% | 3 | 66 | Township |
| Hecla | 13 | 182 | 194 | -1.62% | 529 | 0 | City |
| Mercier | 14 | 165 | 167 | 0.61% | 5 | 36 | Township |
| Columbia | 15 | 156 | 159 | -0.64% | 103 | 2 | City |
| Garden Prairie | 16 | 139 | 142 | -0.71% | 4 | 36 | Township |
| Groton | 17 | 126 | 130 | -0.79% | 3 | 46 | Township |
| Claremont | 18 | 122 | 124 | 0% | 2 | 54 | Township |
| Cambria | 19 | 118 | 123 | -0.84% | 3 | 36 | Township |
| East Hanson | 20 | 110 | 114 | -0.9% | 3 | 36 | Township |
| Claremont | 21 | 105 | 109 | -0.94% | 418 | 0 | Town |
| Oneota | 22 | 103 | 107 | -0.96% | 3 | 36 | Township |
| Columbia | 23 | 102 | 104 | 0% | 2 | 48 | Township |
| Brainard | 24 | 100 | 104 | -0.99% | 2 | 53 | Township |
| New Hope | 25 | 99 | 102 | -1% | 3 | 36 | Township |
| Putney | 26 | 87 | 90 | -1.14% | 2 | 36 | Township |
| Westport | 27 | 84 | 87 | -1.18% | 3 | 29 | Township |
| Westport | 28 | 82 | 87 | -1.2% | 349 | 0 | Town |
| East Rondell | 29 | 81 | 84 | -1.22% | 2 | 36 | Township |
| Shelby | 30 | 80 | 82 | 0% | 2 | 49 | Township |
| Highland | 31 | 76 | 77 | 0% | 2 | 36 | Township |
| Garland | 32 | 75 | 69 | 2.74% | 3 | 30 | Township |
| Richland | 33 | 66 | 64 | 3.13% | 2 | 36 | Township |
| West Rondell | 34 | 65 | 66 | 0% | 2 | 34 | Township |
| Palmyra | 35 | 61 | 61 | 1.67% | 2 | 34 | Township |
| Riverside | 36 | 60 | 64 | -1.64% | 2 | 36 | Township |
| Stratford | 37 | 58 | 60 | -1.69% | 232 | 0 | Town |
| South Detroit | 38 | 52 | 50 | 4% | 1 | 36 | Township |
| Savo | 39 | 50 | 52 | -1.96% | 1 | 36 | Township |
| West Hanson | 40 | 49 | 47 | 4.26% | 1 | 36 | Township |
| Frederick | 41 | 47 | 49 | -2.08% | 1 | 35 | Township |
| North Detroit | 42 | 47 | 49 | 0% | 1 | 36 | Township |
| Liberty | 43 | 42 | 44 | -2.33% | 1 | 47 | Township |
| Osceola | 44 | 40 | 37 | 5.26% | 1 | 36 | Township |
| Greenfield | 45 | 36 | 36 | 0% | 1 | 33 | Township |
| Portage | 46 | 34 | 37 | -2.86% | 1 | 36 | Township |
| Carlisle | 47 | 32 | 33 | 0% | 1 | 36 | Township |
| Franklyn | 48 | 30 | 31 | 0% | 1 | 36 | Township |
| Hecla | 49 | 28 | 29 | 0% | 1 | 24 | Township |
| Allison | 50 | 27 | 26 | 0% | 1 | 36 | Township |
| Lansing | 51 | 27 | 28 | 0% | 1 | 34 | Township |
| Bates | 52 | 25 | 26 | 0% | 1 | 36 | Township |
| Wetonka | 53 | 12 | 14 | -7.69% | 49 | 0 | Town |
| Verdon | 54 | 6 | 6 | 0% | 24 | 0 | Town |
Aberdeen is the largest city in Brown County, with a population of 27,789.
Verdon is the smallest city in Brown County, with a population of 6.
There are 54 cities in Brown County, South Dakota.