20 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Center | 1 | 3,307 | 3,440 | -0.93% | 80 | 41 | Township |
| Jerusalem | 2 | 2,906 | 2,902 | 0.07% | 98 | 30 | Township |
| Woodsfield | 3 | 2,116 | 2,202 | -0.66% | 1,050 | 2 | Village |
| Sunsbury | 4 | 1,216 | 1,276 | -0.98% | 43 | 28 | Township |
| Malaga | 5 | 1,006 | 1,049 | -0.89% | 34 | 29 | Township |
| Lee | 6 | 863 | 898 | -0.8% | 50 | 17 | Township |
| Ohio | 7 | 815 | 849 | -0.85% | 35 | 23 | Township |
| Matamoras (New Matamoras) | 8 | 676 | 703 | -0.59% | 1,943 | 0 | Village |
| Adams | 9 | 622 | 635 | -0.48% | 28 | 22 | Township |
| Summit | 10 | 568 | 602 | -1.22% | 25 | 23 | Township |
| Seneca | 11 | 415 | 433 | -0.72% | 18 | 22 | Township |
| Switzerland | 12 | 405 | 417 | -0.74% | 15 | 27 | Township |
| Washington | 13 | 391 | 410 | -1.01% | 13 | 31 | Township |
| Beallsville | 14 | 339 | 351 | -0.59% | 934 | 0 | Village |
| Benton | 15 | 269 | 280 | -0.74% | 12 | 23 | Township |
| Clarington | 16 | 267 | 279 | -0.74% | 256 | 1 | Village |
| Jerusalem | 17 | 119 | 124 | -0.83% | 492 | 0 | Village |
| Antioch | 18 | 72 | 75 | 0% | 699 | 0 | Village |
| Stafford | 19 | 66 | 69 | 0% | 194 | 0 | Village |
| Miltonsburg | 20 | 38 | 40 | 0% | 521 | 0 | Village |
Center is the largest city in Monroe County, with a population of 3,307.
Miltonsburg is the smallest city in Monroe County, with a population of 38.
There are 20 cities in Monroe County, Ohio.