| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton | 1 | 64,817 | 63,443 | 0.27% | 3,022 | 21 | City |
| Middletown | 2 | 52,411 | 51,037 | 0.51% | 1,989 | 26 | City |
| Fairfield | 3 | 44,657 | 44,896 | -0.06% | 2,143 | 21 | City |
| Oxford | 4 | 22,236 | 23,031 | -0.67% | 2,860 | 8 | City |
| Monroe | 5 | 15,967 | 15,449 | 0.55% | 1,012 | 16 | City |
| Trenton | 6 | 14,488 | 13,056 | 1.73% | 2,934 | 5 | City |
| Sharonville | 7 | 13,972 | 14,097 | -0.18% | 1,425 | 10 | City |
| New Miami | 8 | 2,300 | 2,216 | 0.57% | 2,544 | 1 | Village |
| Glendale | 9 | 2,281 | 2,303 | -0.18% | 1,389 | 2 | Village |
| Seven Mile | 10 | 741 | 716 | 0.54% | 1,025 | 1 | Village |
| Millville | 11 | 644 | 628 | 0.31% | 1,105 | 1 | Village |
| College Corner | 12 | 399 | 391 | 0.25% | 1,596 | 0 | Village |
| Jacksonburg | 13 | 53 | 53 | 0% | 2,650 | 0 | Village |
Hamilton is the largest city in Butler County, with a population of 64,817.
Jacksonburg is the smallest city in Butler County, with a population of 53.
There are 13 cities in Butler County, Ohio.