23 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cambridge | 1 | 13,829 | 13,898 | 0.2% | 397 | 35 | Township |
| Cambridge | 2 | 10,017 | 10,111 | -0.19% | 1,573 | 6 | City |
| Byesville | 3 | 2,342 | 2,364 | -0.21% | 1,955 | 1 | Village |
| Westland | 4 | 2,185 | 2,184 | 0.37% | 86 | 25 | Township |
| Richland | 5 | 2,056 | 2,060 | 0.34% | 74 | 28 | Township |
| Valley | 6 | 2,019 | 2,026 | 0.2% | 89 | 23 | Township |
| Adams | 7 | 1,871 | 1,878 | 0.21% | 74 | 25 | Township |
| Center | 8 | 1,713 | 1,725 | 0.12% | 71 | 24 | Township |
| Wills | 9 | 1,504 | 1,508 | 0.2% | 41 | 36 | Township |
| Millwood | 10 | 1,220 | 1,230 | 0.08% | 45 | 27 | Township |
| Liberty | 11 | 907 | 912 | 0.22% | 38 | 24 | Township |
| Buffalo | 12 | 902 | 908 | -0.55% | 37 | 24 | Township |
| Wheeling | 13 | 683 | 679 | 0.29% | 21 | 32 | Township |
| Knox | 14 | 532 | 528 | 0.57% | 21 | 25 | Township |
| Washington | 15 | 463 | 464 | 0.22% | 19 | 25 | Township |
| Senecaville | 16 | 413 | 418 | -0.24% | 869 | 0 | Village |
| Pleasant City | 17 | 388 | 396 | -0.51% | 2,205 | 0 | Village |
| Quaker City | 18 | 373 | 380 | -0.53% | 709 | 1 | Village |
| Cumberland | 19 | 313 | 317 | -0.32% | 644 | 0 | Village |
| Lore City | 20 | 276 | 283 | -0.72% | 841 | 0 | Village |
| Old Washington | 21 | 221 | 224 | -0.45% | 329 | 1 | Village |
| Batesville | 22 | 98 | 101 | -1.01% | 434 | 0 | Village |
| Fairview | 23 | 68 | 70 | -1.45% | 170 | 0 | Village |
Cambridge is the largest city in Guernsey County, with a population of 13,829.
Fairview is the smallest city in Guernsey County, with a population of 68.
There are 23 cities in Guernsey County, Ohio.