5 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 |
| Wentworth | 2 | 164 | 179 | -1.2% | 646 | 0 | Village |
| Ramona | 3 | 161 | 161 | 0% | 588 | 0 | Town |
| Brant Lake | 4 | 55 | 57 | 0% | 355 | 0 | City |
| Nunda | 5 | 50 | 47 | 2.04% | 50 | 1 | Town |
Madison is the largest city in Lake County, with a population of 6,048.
Nunda is the smallest city in Lake County, with a population of 50.
There are 5 cities in Lake County, South Dakota.