| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sedalia | 1 | 22,774 | 21,741 | 0.68% | 1,515 | 15 | City |
| La Monte | 2 | 1,019 | 1,006 | 0.1% | 939 | 1 | City |
| Green Ridge | 3 | 633 | 469 | 5.32% | 1,476 | 0 | City |
| Smithton | 4 | 508 | 505 | 0% | 1,688 | 0 | City |
| Houstonia | 5 | 201 | 199 | 0% | 1,015 | 0 | City |
| Hughesville | 6 | 151 | 150 | 0% | 1,302 | 0 | Village |
Sedalia is the largest city in Pettis County, with a population of 22,774.
Hughesville is the smallest city in Pettis County, with a population of 151.
There are 6 cities in Pettis County, Missouri.