| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Montgomery City | 1 | 2,781 | 2,801 | -0.04% | 824 | 3 | City |
| Wellsville | 2 | 1,017 | 991 | 0.49% | 662 | 2 | City |
| Jonesburg | 3 | 887 | 724 | 2.66% | 442 | 2 | City |
| New Florence | 4 | 650 | 640 | 0% | 216 | 3 | City |
| Bellflower | 5 | 339 | 328 | 0.59% | 606 | 1 | City |
| High Hill | 6 | 186 | 187 | 0% | 404 | 0 | City |
| Middletown | 7 | 169 | 170 | 0% | 526 | 0 | Town |
| Rhineland | 8 | 137 | 139 | -0.72% | 407 | 0 | Town |
Montgomery City is the largest city in Montgomery County, with a population of 2,781.
Rhineland is the smallest city in Montgomery County, with a population of 137.
There are 8 cities in Montgomery County, Missouri.