26 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Liberty | 1 | 10,459 | 10,192 | 0.46% | 178 | 59 | Township |
| Hillsboro | 2 | 6,674 | 6,448 | 0.57% | 1,219 | 5 | City |
| Greenfield | 3 | 6,034 | 5,753 | 0.9% | 192 | 31 | Township |
| Paint | 4 | 4,954 | 4,841 | 0.55% | 89 | 56 | Township |
| Greenfield | 5 | 4,354 | 4,342 | 0.05% | 2,087 | 2 | Village |
| Dodson | 6 | 2,631 | 2,565 | 0.65% | 101 | 26 | Township |
| Highland | 7 | 2,318 | 2,292 | 0.43% | 65 | 36 | Township |
| Union | 8 | 1,973 | 1,943 | 0.41% | 67 | 30 | Township |
| New Market | 9 | 1,903 | 1,882 | 0.32% | 71 | 27 | Township |
| Leesburg | 10 | 1,757 | 1,433 | 2.99% | 58 | 30 | Township |
| Penn | 11 | 1,578 | 1,555 | 0.45% | 49 | 32 | Township |
| Lynchburg | 12 | 1,558 | 1,516 | 0.45% | 1,688 | 1 | Village |
| Clay | 13 | 1,537 | 1,523 | 0.33% | 55 | 28 | Township |
| Brushcreek | 14 | 1,448 | 1,421 | 0.42% | 33 | 43 | Township |
| Concord | 15 | 1,408 | 1,381 | 0.43% | 42 | 34 | Township |
| Whiteoak | 16 | 1,342 | 1,328 | 0.3% | 44 | 30 | Township |
| Greenfield | 17 | 1,323 | 1,352 | -0.23% | 52 | 25 | Township |
| Leesburg | 18 | 1,287 | 1,274 | 0.16% | 1,102 | 1 | Village |
| Washington | 19 | 1,084 | 1,070 | 0.37% | 44 | 24 | Township |
| Marshall | 20 | 1,042 | 1,032 | 0.39% | 48 | 22 | Township |
| Highland | 21 | 914 | 920 | -0.11% | 36 | 25 | Township |
| Hamer | 22 | 677 | 670 | 0.45% | 30 | 23 | Township |
| Greenfield | 23 | 467 | 477 | -0.43% | 14 | 33 | Township |
| Mowrystown | 24 | 386 | 386 | 0% | 801 | 0 | Village |
| Highland | 25 | 232 | 229 | 0.43% | 1,365 | 0 | Village |
| Sinking Spring | 26 | 122 | 121 | 0% | 261 | 0 | Village |
Liberty is the largest city in Highland County, with a population of 10,459.
Sinking Spring is the smallest city in Highland County, with a population of 122.
There are 26 cities in Highland County, Ohio.