6 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sedalia | 1 | 22,313 | 21,745 | 0.51% | 1,561 | 14.29 | City |
| La Monte | 2 | 1,010 | 1,005 | 0.1% | 931 | 1.08 | City |
| Green Ridge | 3 | 686 | 470 | 6.69% | 1,599 | 0.43 | City |
| Smithton | 4 | 505 | 507 | 0% | 1,678 | 0.30 | City |
| Houstonia | 5 | 197 | 196 | 0% | 995 | 0.20 | City |
| Hughesville | 6 | 151 | 150 | 0% | 1,302 | 0.12 | Village |
Sedalia is the largest city in Pettis County, with a population of 22,313.
Hughesville is the smallest city in Pettis County.
There are 6 cities in Pettis County, Missouri.