13 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton | 1 | 64,220 | 63,419 | 0.21% | 2,994 | 21 | City |
| Middletown | 2 | 52,925 | 51,023 | 0.6% | 2,009 | 26 | City |
| Fairfield | 3 | 45,185 | 44,912 | 0.1% | 2,169 | 21 | City |
| Oxford | 4 | 22,354 | 23,047 | -0.51% | 2,875 | 8 | City |
| Monroe | 5 | 16,195 | 15,460 | 0.77% | 1,026 | 16 | City |
| Trenton | 6 | 14,660 | 13,072 | 1.84% | 2,969 | 5 | City |
| Sharonville | 7 | 14,008 | 14,103 | -0.11% | 1,428 | 10 | City |
| New Miami | 8 | 2,307 | 2,214 | 0.7% | 2,552 | 1 | Village |
| Glendale | 9 | 2,273 | 2,299 | -0.18% | 1,384 | 2 | Village |
| Seven Mile | 10 | 754 | 721 | 0.8% | 1,043 | 1 | Village |
| Millville | 11 | 659 | 637 | 0.61% | 1,130 | 1 | Village |
| College Corner | 12 | 401 | 389 | 0.5% | 1,604 | 0 | Village |
| Jacksonburg | 13 | 53 | 53 | 0% | 2,650 | 0 | Village |
Hamilton is the largest city in Butler County, with a population of 64,220.
Jacksonburg is the smallest city in Butler County, with a population of 53.
There are 13 cities in Butler County, Ohio.