11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kent Estates | 1 | 2,555 | 1,991 | 7.13% | 562 | 4.55 | CDP |
| Wapello | 2 | 1,966 | 2,083 | -1.16% | 1,513 | 1.30 | City |
| Columbus Junction | 3 | 1,731 | 1,830 | -1.14% | 806 | 2.15 | City |
| Morning Sun | 4 | 657 | 746 | -2.67% | 846 | 0.78 | City |
| Grandview | 5 | 420 | 442 | -0.94% | 1,842 | 0.23 | City |
| Columbus City | 6 | 372 | 386 | -0.8% | 1,550 | 0.24 | City |
| Letts | 7 | 349 | 361 | -0.57% | 616 | 0.57 | City |
| Fairport | 8 | 285 | 268 | 7.14% | 153 | 1.86 | CDP |
| Fredonia | 9 | 205 | 219 | -1.44% | 1,358 | 0.15 | City |
| Oakville | 10 | 187 | 199 | -1.06% | 448 | 0.42 | City |
| Cotter | 11 | 36 | 38 | 0% | 367 | 0.10 | City |
Kent Estates is the largest city in Louisa County, with a population of 2,555.
Cotter is the smallest city in Louisa County.
There are 11 cities in Louisa County, Iowa.