| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hillsboro | 1 | 6,796 | 6,439 | 0.49% | 1,241 | 5 | City |
| Greenfield | 2 | 4,329 | 4,344 | 0% | 2,075 | 2 | Village |
| Lynchburg | 3 | 1,544 | 1,513 | 0.39% | 1,673 | 1 | Village |
| Leesburg | 4 | 1,282 | 1,270 | 0.16% | 1,098 | 1 | Village |
| Mowrystown | 5 | 387 | 386 | 0% | 803 | 0 | Village |
| Highland | 6 | 229 | 228 | 0% | 1,347 | 0 | Village |
| Sinking Spring | 7 | 120 | 120 | 0% | 257 | 0 | Village |
Hillsboro is the largest city in Highland County, with a population of 6,796.
Sinking Spring is the smallest city in Highland County, with a population of 120.
There are 7 cities in Highland County, Ohio.