23 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Madison | 1 | 6,048 | 6,161 | -0.31% | 1,310 | 5 | City |
| Lake View | 2 | 815 | 800 | -0.12% | 29 | 28 | Township |
| Chester | 3 | 686 | 678 | -0.29% | 21 | 33 | Township |
| Herman | 4 | 675 | 672 | -0.44% | 21 | 33 | Township |
| Wentworth | 5 | 513 | 501 | 0% | 15 | 34 | Township |
| Franklin | 6 | 323 | 325 | -0.62% | 9 | 36 | Township |
| Farmington | 7 | 209 | 206 | 0% | 6 | 36 | Township |
| Le Roy | 8 | 196 | 193 | 0% | 5 | 36 | Township |
| Rutland | 9 | 187 | 189 | -1.06% | 5 | 36 | Township |
| Wentworth | 10 | 164 | 179 | -1.2% | 646 | 0 | Village |
| Ramona | 11 | 161 | 161 | 0% | 588 | 0 | Town |
| Madison | 12 | 129 | 127 | 0% | 4 | 36 | Township |
| Winfred | 13 | 129 | 124 | 0.78% | 4 | 36 | Township |
| Nunda | 14 | 110 | 111 | -0.9% | 3 | 35 | Township |
| Orland | 15 | 99 | 92 | 2.06% | 3 | 36 | Township |
| Badus | 16 | 91 | 91 | -1.09% | 3 | 35 | Township |
| Concord | 17 | 91 | 91 | -1.09% | 3 | 36 | Township |
| Chester | 18 | 87 | 87 | 0% | 3 | 28 | Township |
| Wayne | 19 | 86 | 82 | 1.18% | 2 | 36 | Township |
| Clarno | 20 | 68 | 71 | -1.45% | 2 | 36 | Township |
| Brant Lake | 21 | 55 | 57 | 0% | 355 | 0 | City |
| Nunda | 22 | 50 | 47 | 2.04% | 50 | 1 | Town |
| Madison | 23 | 15 | 15 | 0% | 0.00 | 35 | Township |
Madison is the largest city in Lake County, with a population of 6,048.
Madison is the smallest city in Lake County, with a population of 15.
There are 23 cities in Lake County, South Dakota.