13 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cambridge | 1 | 9,894 | 10,081 | -0.37% | 1,554 | 6.37 | City |
| Byesville | 2 | 2,325 | 2,364 | -0.34% | 1,941 | 1.20 | Village |
| Buffalo | 3 | 892 | 636 | 3.72% | 1,820 | 0.49 | CDP |
| Senecaville | 4 | 411 | 420 | -0.48% | 865 | 0.47 | Village |
| Pleasant City | 5 | 385 | 397 | -0.52% | 2,188 | 0.18 | Village |
| Quaker City | 6 | 378 | 380 | 0% | 719 | 0.53 | Village |
| Cumberland | 7 | 309 | 316 | -0.32% | 636 | 0.49 | Village |
| Lore City | 8 | 279 | 284 | -0.36% | 851 | 0.33 | Village |
| Old Washington | 9 | 221 | 226 | -0.45% | 329 | 0.67 | Village |
| Salesville | 10 | 188 | 86 | 7.43% | 969 | 0.19 | CDP |
| Kimbolton | 11 | 126 | 26 | -1.56% | 253 | 0.50 | CDP |
| Batesville | 12 | 99 | 101 | 0% | 438 | 0.23 | Village |
| Fairview | 13 | 69 | 68 | 0% | 172 | 0.40 | Village |
Cambridge is the largest city in Guernsey County, with a population of 9,894.
Fairview is the smallest city in Guernsey County.
There are 13 cities in Guernsey County, Ohio.