27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Liberty | 1 | 10,415 | 10,195 | 0.42% | 177 | 59 | Township |
| Hillsboro | 2 | 6,702 | 6,489 | 0.65% | 1,224 | 5 | City |
| Greenfield | 3 | 5,977 | 5,750 | 1.03% | 190 | 31 | Township |
| Paint | 4 | 4,936 | 4,839 | 0.59% | 88 | 56 | Township |
| Greenfield | 5 | 4,332 | 4,341 | -0.05% | 2,077 | 2 | Village |
| Dodson | 6 | 2,612 | 2,566 | 0.58% | 100 | 26 | Township |
| Highland | 7 | 2,297 | 2,290 | 0.44% | 64 | 36 | Township |
| Union | 8 | 1,982 | 1,943 | 0.61% | 67 | 30 | Township |
| New Market | 9 | 1,908 | 1,881 | 0.47% | 71 | 27 | Township |
| Leesburg | 10 | 1,728 | 1,431 | 3.85% | 57 | 30 | Township |
| Penn | 11 | 1,568 | 1,555 | 0.38% | 49 | 32 | Township |
| Lynchburg | 12 | 1,545 | 1,515 | 0.39% | 1,674 | 1 | Village |
| Clay | 13 | 1,536 | 1,523 | 0.33% | 55 | 28 | Township |
| Brushcreek | 14 | 1,429 | 1,421 | 0.35% | 33 | 43 | Township |
| Concord | 15 | 1,394 | 1,381 | 0.36% | 41 | 34 | Township |
| Whiteoak | 16 | 1,343 | 1,329 | 0.37% | 44 | 30 | Township |
| Greenfield | 17 | 1,323 | 1,357 | -0.45% | 52 | 25 | Township |
| Leesburg | 18 | 1,288 | 1,268 | 0.31% | 1,103 | 1 | Village |
| Washington | 19 | 1,081 | 1,070 | 0.37% | 44 | 24 | Township |
| Marshall | 20 | 1,037 | 1,034 | 0.19% | 47 | 22 | Township |
| Highland | 21 | 925 | 920 | 0.33% | 37 | 25 | Township |
| Hamer | 22 | 674 | 669 | 0.3% | 30 | 23 | Township |
| Greenfield | 23 | 468 | 478 | -0.43% | 14 | 33 | Township |
| Buford | 24 | 461 | 280 | 1.54% | 311 | 1 | CDP |
| Mowrystown | 25 | 385 | 387 | 0% | 799 | 0 | Village |
| Highland | 26 | 227 | 229 | 0% | 1,335 | 0 | Village |
| Sinking Spring | 27 | 121 | 121 | 0% | 259 | 0 | Village |
Liberty is the largest city in Highland County, with a population of 10,415.
Sinking Spring is the smallest city in Highland County, with a population of 121.
There are 27 cities in Highland County, Ohio.