27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Pleasant | 1 | 5,776 | 5,662 | 0.94% | 161 | 36 | Township |
| Georgetown | 2 | 4,508 | 4,456 | 0.22% | 1,085 | 4 | Village |
| Mount Orab | 3 | 4,411 | 4,353 | 0.25% | 455 | 10 | Village |
| Pike | 4 | 4,194 | 4,104 | 0.96% | 173 | 24 | Township |
| Clark | 5 | 2,994 | 2,935 | 0.94% | 101 | 30 | Township |
| Union | 6 | 2,795 | 2,740 | 0.94% | 74 | 38 | Township |
| Huntington | 7 | 2,547 | 2,472 | 1.15% | 76 | 34 | Township |
| Lewis | 8 | 2,480 | 2,401 | 1.14% | 58 | 43 | Township |
| Ripley | 9 | 2,470 | 2,440 | 0.45% | 84 | 29 | Township |
| Washington | 10 | 2,311 | 2,242 | 1.14% | 102 | 23 | Township |
| Ripley | 11 | 1,594 | 1,577 | 0.19% | 801 | 2 | Village |
| Aberdeen | 12 | 1,548 | 1,515 | 0.39% | 1,147 | 1 | Village |
| Eagle | 13 | 1,348 | 1,307 | 1.13% | 53 | 26 | Township |
| Decatur | 14 | 1,295 | 1,310 | -0.08% | 37 | 35 | Township |
| Lake Lorelei | 15 | 1,136 | 1,548 | -0.18% | 516 | 2 | CDP |
| Sardinia | 16 | 1,114 | 1,088 | 0.45% | 635 | 2 | Village |
| Lake Waynoka | 17 | 1,086 | 972 | -0.46% | 254 | 4 | CDP |
| Ripley | 18 | 1,069 | 1,083 | -0.09% | 42 | 26 | Township |
| Highland Holiday | 19 | 1,046 | 677 | 3.26% | 1,732 | 1 | CDP |
| Byrd | 20 | 758 | 743 | 1.07% | 30 | 25 | Township |
| Rocky Fork Point | 21 | 716 | 670 | 0.7% | 1,006 | 1 | CDP |
| Decatur | 22 | 607 | 625 | -0.16% | 18 | 33 | Township |
| Russellville | 23 | 549 | 542 | 0.18% | 753 | 1 | Village |
| Hamersville | 24 | 498 | 492 | 0.2% | 1,137 | 0 | Village |
| Fayetteville | 25 | 317 | 314 | 0% | 672 | 0 | Village |
| Higginsport | 26 | 218 | 215 | 0% | 869 | 0 | Village |
| St. Martin | 27 | 169 | 164 | 6.96% | 87 | 2 | CDP |
Pleasant is the largest city in Brown County, with a population of 5,776.
St. Martin is the smallest city in Brown County, with a population of 169.
There are 27 cities in Brown County, Ohio.