29 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Madison | 1 | 6,045 | 6,159 | -0.38% | 1,310 | 4.62 | City |
| Lake Madison | 2 | 892 | 811 | 1.59% | 189 | 4.72 | CDP |
| Lake View township | 3 | 846 | 800 | 1.68% | 30 | 28.48 | Township |
| Chester township | 4 | 710 | 671 | 1.72% | 21 | 33.19 | Township |
| Herman township | 5 | 705 | 674 | 1.44% | 22 | 32.57 | Township |
| Wentworth township | 6 | 533 | 507 | 1.52% | 16 | 34.14 | Township |
| Franklin township | 7 | 338 | 326 | 1.2% | 9 | 35.89 | Township |
| Brant Lake South | 8 | 279 | 290 | 7.31% | 531 | 0.53 | CDP |
| Chester | 9 | 231 | 285 | -0.86% | 283 | 0.82 | CDP |
| Farmington township | 10 | 217 | 204 | 1.88% | 6 | 35.88 | Township |
| Le Roy township | 11 | 203 | 191 | 2.01% | 6 | 35.97 | Township |
| Rutland township | 12 | 198 | 188 | 1.54% | 6 | 35.86 | Township |
| Wentworth | 13 | 170 | 180 | -1.16% | 669 | 0.25 | Village |
| Ramona | 14 | 164 | 161 | 0.61% | 599 | 0.27 | Town |
| Golden View Colony | 15 | 134 | 102 | 7.2% | 139 | 0.96 | CDP |
| Madison township | 16 | 131 | 127 | 0.77% | 4 | 35.77 | Township |
| Winfred township | 17 | 129 | 125 | 0.78% | 4 | 36.32 | Township |
| Nunda township | 18 | 120 | 112 | 2.56% | 3 | 34.53 | Township |
| Badus township | 19 | 99 | 92 | 2.06% | 3 | 35.14 | Township |
| Concord township | 20 | 98 | 91 | 2.08% | 3 | 36.27 | Township |
| Orland township | 21 | 91 | 92 | -1.09% | 3 | 35.79 | Township |
| Chester township | 22 | 88 | 87 | 1.15% | 3 | 28.16 | Township |
| Wayne township | 23 | 83 | 82 | 0% | 2 | 35.50 | Township |
| Clarno township | 24 | 71 | 71 | 0% | 2 | 36.10 | Township |
| Winfred | 25 | 58 | 68 | 7.41% | 58 | 1 | CDP |
| Brant Lake | 26 | 55 | 57 | 0% | 355 | 0.15 | City |
| Nunda | 27 | 47 | 47 | 0% | 47 | 1.01 | Town |
| Shannon Colony | 28 | 34 | 27 | 6.25% | 135 | 0.25 | CDP |
| Madison township | 29 | 15 | 15 | 0% | 0.00 | 35.14 | Township |
Madison is the largest city in Lake County, with a population of 6,045.
Madison township is the smallest city in Lake County.
There are 29 cities in Lake County, South Dakota.