27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Pleasant | 1 | 5,666 | 5,658 | 0.07% | 158 | 36 | Township |
| Georgetown | 2 | 4,458 | 4,457 | 0% | 1,073 | 4 | Village |
| Mount Orab | 3 | 4,347 | 4,352 | -0.02% | 449 | 10 | Village |
| Pike | 4 | 4,141 | 4,105 | 0.24% | 171 | 24 | Township |
| Clark | 5 | 2,941 | 2,929 | 0.14% | 99 | 30 | Township |
| Union | 6 | 2,743 | 2,738 | 0.11% | 72 | 38 | Township |
| Huntington | 7 | 2,498 | 2,475 | 0.24% | 74 | 34 | Township |
| Ripley | 8 | 2,455 | 2,441 | 0.12% | 83 | 29 | Township |
| Lewis | 9 | 2,447 | 2,406 | 0.41% | 58 | 43 | Township |
| Washington | 10 | 2,266 | 2,241 | 0.31% | 100 | 23 | Township |
| Ripley | 11 | 1,579 | 1,584 | -0.06% | 794 | 2 | Village |
| Aberdeen | 12 | 1,527 | 1,516 | 0.13% | 1,131 | 1 | Village |
| Eagle | 13 | 1,324 | 1,306 | 0.38% | 52 | 26 | Township |
| Decatur | 14 | 1,281 | 1,309 | -0.39% | 37 | 35 | Township |
| Lake Lorelei | 15 | 1,136 | 1,548 | -0.18% | 516 | 2 | CDP |
| Sardinia | 16 | 1,091 | 1,085 | 0.09% | 622 | 2 | Village |
| Lake Waynoka | 17 | 1,086 | 972 | -0.46% | 254 | 4 | CDP |
| Ripley | 18 | 1,066 | 1,082 | -0.28% | 42 | 26 | Township |
| Highland Holiday | 19 | 1,046 | 677 | 3.26% | 1,732 | 1 | CDP |
| Byrd | 20 | 747 | 742 | 0.27% | 30 | 25 | Township |
| Rocky Fork Point | 21 | 716 | 670 | 0.7% | 1,006 | 1 | CDP |
| Decatur | 22 | 605 | 625 | -0.49% | 18 | 33 | Township |
| Russellville | 23 | 540 | 542 | 0% | 741 | 1 | Village |
| Hamersville | 24 | 487 | 487 | 0% | 1,112 | 0 | Village |
| Fayetteville | 25 | 309 | 311 | 0% | 655 | 0 | Village |
| Higginsport | 26 | 216 | 216 | 0% | 861 | 0 | Village |
| St. Martin | 27 | 169 | 164 | 6.96% | 87 | 2 | CDP |
Pleasant is the largest city in Brown County, with a population of 5,666.
St. Martin is the smallest city in Brown County, with a population of 169.
There are 27 cities in Brown County, Ohio.