27 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Liberty | 1 | 10,411 | 10,192 | 0.46% | 177 | 59 | Township |
| Hillsboro | 2 | 6,636 | 6,448 | 0.56% | 1,212 | 5 | City |
| Greenfield | 3 | 5,980 | 5,753 | 0.91% | 190 | 31 | Township |
| Paint | 4 | 4,927 | 4,841 | 0.55% | 88 | 56 | Township |
| Greenfield | 5 | 4,352 | 4,342 | 0.05% | 2,086 | 2 | Village |
| Dodson | 6 | 2,614 | 2,565 | 0.65% | 100 | 26 | Township |
| Highland | 7 | 2,308 | 2,292 | 0.44% | 64 | 36 | Township |
| Union | 8 | 1,965 | 1,943 | 0.41% | 66 | 30 | Township |
| New Market | 9 | 1,897 | 1,882 | 0.32% | 71 | 27 | Township |
| Leesburg | 10 | 1,706 | 1,433 | 3.08% | 57 | 30 | Township |
| Penn | 11 | 1,571 | 1,555 | 0.45% | 49 | 32 | Township |
| Lynchburg | 12 | 1,551 | 1,516 | 0.45% | 1,680 | 1 | Village |
| Clay | 13 | 1,532 | 1,523 | 0.33% | 55 | 28 | Township |
| Brushcreek | 14 | 1,442 | 1,421 | 0.42% | 33 | 43 | Township |
| Concord | 15 | 1,402 | 1,381 | 0.43% | 42 | 34 | Township |
| Whiteoak | 16 | 1,338 | 1,328 | 0.3% | 44 | 30 | Township |
| Greenfield | 17 | 1,326 | 1,352 | -0.23% | 53 | 25 | Township |
| Leesburg | 18 | 1,285 | 1,274 | 0.16% | 1,100 | 1 | Village |
| Washington | 19 | 1,080 | 1,070 | 0.37% | 44 | 24 | Township |
| Marshall | 20 | 1,038 | 1,032 | 0.39% | 47 | 22 | Township |
| Highland | 21 | 915 | 920 | -0.11% | 36 | 25 | Township |
| Hamer | 22 | 674 | 670 | 0.45% | 30 | 23 | Township |
| Greenfield | 23 | 469 | 477 | -0.42% | 14 | 33 | Township |
| Buford | 24 | 461 | 280 | 1.54% | 311 | 1 | CDP |
| Mowrystown | 25 | 386 | 386 | 0% | 801 | 0 | Village |
| Highland | 26 | 231 | 229 | 0% | 1,359 | 0 | Village |
| Sinking Spring | 27 | 122 | 121 | 0% | 261 | 0 | Village |
Liberty is the largest city in Highland County, with a population of 10,411.
Sinking Spring is the smallest city in Highland County, with a population of 122.
There are 27 cities in Highland County, Ohio.