7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Canton | 1 | 2,712 | 2,772 | -0.44% | 1,187 | 2 | City |
| La Grange | 2 | 787 | 826 | -1.01% | 506 | 2 | City |
| La Belle | 3 | 635 | 664 | -0.94% | 934 | 1 | City |
| Lewistown | 4 | 497 | 519 | -0.8% | 992 | 1 | Town |
| Ewing | 5 | 383 | 400 | -0.78% | 614 | 1 | City |
| Monticello | 6 | 102 | 106 | -0.97% | 391 | 0 | Village |
| Williamstown | 7 | 50 | 84 | 6.38% | 185 | 0 | CDP |
Canton is the largest city in Lewis County, with a population of 2,712.
Williamstown is the smallest city in Lewis County, with a population of 50.
There are 7 cities in Lewis County, Missouri.