43 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Cadiz | 1 | 3,244 | 3,392 | -1.07% | 94 | 34 | Township |
| Cadiz | 2 | 3,244 | 3,392 | -1.07% | 94 | 34 | Township |
| Cadiz | 3 | 2,924 | 3,054 | -0.88% | 333 | 9 | Village |
| Cadiz | 4 | 2,924 | 3,054 | -0.88% | 333 | 9 | Village |
| Harrisville | 5 | 1,755 | 1,717 | 0.46% | 73 | 24 | Township |
| Harrisville | 6 | 1,755 | 1,719 | 0.46% | 73 | 24 | Township |
| North | 7 | 1,527 | 1,601 | -1.17% | 66 | 23 | Township |
| North | 8 | 1,527 | 1,601 | -1.17% | 66 | 23 | Township |
| Rumley | 9 | 1,225 | 1,276 | -0.97% | 53 | 23 | Township |
| Rumley | 10 | 1,225 | 1,277 | -0.97% | 53 | 23 | Township |
| Short Creek | 11 | 972 | 1,016 | -1.12% | 32 | 30 | Township |
| Short Creek | 12 | 972 | 1,016 | -1.12% | 32 | 30 | Township |
| Hopedale | 13 | 892 | 921 | -0.78% | 761 | 1 | Village |
| Hopedale | 14 | 892 | 924 | -0.78% | 761 | 1 | Village |
| Freeport | 15 | 704 | 730 | -0.98% | 29 | 24 | Township |
| Freeport | 16 | 704 | 730 | -0.98% | 29 | 24 | Township |
| German | 17 | 700 | 721 | -0.99% | 28 | 25 | Township |
| German | 18 | 700 | 722 | -0.99% | 28 | 25 | Township |
| Scio | 19 | 640 | 671 | -0.93% | 1,149 | 1 | Village |
| Scio | 20 | 640 | 670 | -0.93% | 1,149 | 1 | Village |
| Washington | 21 | 589 | 613 | -0.84% | 19 | 30 | Township |
| Washington | 22 | 589 | 613 | -0.84% | 19 | 30 | Township |
| Jewett | 23 | 527 | 552 | -0.94% | 1,035 | 1 | Village |
| Jewett | 24 | 527 | 552 | -0.94% | 1,035 | 1 | Village |
| Stock | 25 | 425 | 443 | -0.93% | 17 | 25 | Township |
| Stock | 26 | 425 | 443 | -0.93% | 17 | 25 | Township |
| Moorefield | 27 | 383 | 393 | -0.52% | 14 | 27 | Township |
| Moorefield | 28 | 383 | 393 | -0.52% | 14 | 27 | Township |
| Bowerston | 29 | 345 | 359 | -0.86% | 682 | 1 | Village |
| Bowerston | 30 | 345 | 359 | -0.86% | 682 | 1 | Village |
| Freeport | 31 | 310 | 322 | -0.96% | 518 | 1 | Village |
| Freeport | 32 | 310 | 322 | -0.96% | 518 | 1 | Village |
| Nottingham | 33 | 289 | 303 | -1.37% | 10 | 28 | Township |
| Nottingham | 34 | 289 | 303 | -1.37% | 10 | 28 | Township |
| Archer | 35 | 278 | 288 | -0.71% | 11 | 25 | Township |
| Archer | 36 | 278 | 288 | -0.71% | 11 | 25 | Township |
| New Athens | 37 | 210 | 220 | -0.94% | 729 | 0 | Village |
| New Athens | 38 | 210 | 220 | -0.94% | 729 | 0 | Village |
| Harrisville | 39 | 171 | 178 | -1.16% | 1,125 | 0 | Village |
| Harrisville | 40 | 171 | 178 | -1.16% | 1,125 | 0 | Village |
| Tippecanoe | 41 | 91 | 97 | -2.15% | 169 | 1 | CDP |
| Deersville | 42 | 63 | 66 | -1.56% | 183 | 0 | Village |
| Deersville | 43 | 63 | 66 | -1.56% | 183 | 0 | Village |
Cadiz is the largest city in Harrison County, with a population of 3,244.
Deersville is the smallest city in Harrison County, with a population of 63.
There are 43 cities in Harrison County, Ohio.