23 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cambridge | 1 | 13,857 | 13,898 | 0.2% | 398 | 35 | Township |
| Cambridge | 2 | 9,998 | 10,111 | -0.19% | 1,570 | 6 | City |
| Byesville | 3 | 2,338 | 2,364 | -0.17% | 1,952 | 1 | Village |
| Westland | 4 | 2,193 | 2,184 | 0.37% | 87 | 25 | Township |
| Richland | 5 | 2,063 | 2,060 | 0.34% | 74 | 28 | Township |
| Valley | 6 | 2,023 | 2,026 | 0.2% | 90 | 23 | Township |
| Adams | 7 | 1,875 | 1,878 | 0.21% | 74 | 25 | Township |
| Center | 8 | 1,715 | 1,725 | 0.12% | 71 | 24 | Township |
| Wills | 9 | 1,507 | 1,508 | 0.2% | 41 | 36 | Township |
| Millwood | 10 | 1,221 | 1,230 | 0.08% | 45 | 27 | Township |
| Liberty | 11 | 909 | 912 | 0.22% | 38 | 24 | Township |
| Buffalo | 12 | 897 | 908 | -0.55% | 37 | 24 | Township |
| Wheeling | 13 | 685 | 679 | 0.29% | 21 | 32 | Township |
| Knox | 14 | 535 | 528 | 0.56% | 21 | 25 | Township |
| Washington | 15 | 464 | 464 | 0.22% | 19 | 25 | Township |
| Senecaville | 16 | 412 | 418 | -0.24% | 867 | 0 | Village |
| Pleasant City | 17 | 387 | 396 | -0.26% | 2,199 | 0 | Village |
| Quaker City | 18 | 372 | 380 | -0.27% | 707 | 1 | Village |
| Cumberland | 19 | 312 | 317 | -0.32% | 642 | 0 | Village |
| Lore City | 20 | 275 | 283 | -0.36% | 838 | 0 | Village |
| Old Washington | 21 | 221 | 224 | 0% | 329 | 1 | Village |
| Batesville | 22 | 98 | 101 | 0% | 434 | 0 | Village |
| Fairview | 23 | 68 | 70 | 0% | 170 | 0 | Village |
Cambridge is the largest city in Guernsey County, with a population of 13,857.
Fairview is the smallest city in Guernsey County, with a population of 68.
There are 23 cities in Guernsey County, Ohio.