| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Dayton | 1 | 136,392 | 137,407 | -0.22% | 2,444 | 56 | City |
| Kettering | 2 | 57,257 | 57,777 | -0.24% | 3,059 | 19 | City |
| Centerville | 3 | 25,338 | 24,491 | 0.57% | 2,309 | 11 | City |
| Riverside | 4 | 24,727 | 24,477 | 0.08% | 2,542 | 10 | City |
| Miamisburg | 5 | 20,503 | 19,904 | 0.44% | 1,673 | 12 | City |
| Vandalia | 6 | 14,977 | 15,098 | -0.25% | 1,214 | 12 | City |
| Clayton | 7 | 13,404 | 13,293 | 0.05% | 724 | 19 | City |
| Englewood | 8 | 13,305 | 13,451 | -0.28% | 2,028 | 7 | City |
| West Carrollton | 9 | 12,921 | 13,074 | -0.32% | 2,010 | 6 | City |
| Moraine | 10 | 6,672 | 6,430 | 0.68% | 719 | 9 | City |
| Brookville | 11 | 5,992 | 5,992 | -0.12% | 1,462 | 4 | City |
| Germantown | 12 | 5,967 | 5,798 | 0.34% | 1,413 | 4 | City |
| Carlisle | 13 | 5,964 | 5,515 | 1.34% | 1,676 | 4 | Village |
| New Lebanon | 14 | 3,882 | 3,795 | 0.31% | 1,898 | 2 | Village |
| Farmersville | 15 | 1,011 | 974 | 0.5% | 1,414 | 1 | Village |
| Phillipsburg | 16 | 493 | 491 | 0% | 1,853 | 0 | Village |
Dayton is the largest city in Montgomery County, with a population of 136,392.
Phillipsburg is the smallest city in Montgomery County, with a population of 493.
There are 16 cities in Montgomery County, Ohio.