17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portsmouth | 1 | 17,309 | 18,207 | -1.03% | 1,613 | 11 | City |
| Porter | 2 | 9,456 | 9,782 | -0.56% | 457 | 21 | Township |
| Washington | 3 | 5,081 | 5,271 | -0.65% | 204 | 25 | Township |
| Valley | 4 | 3,529 | 3,594 | -0.51% | 143 | 25 | Township |
| Clay | 5 | 3,420 | 3,513 | -0.41% | 158 | 22 | Township |
| Rush | 6 | 2,800 | 2,887 | -0.53% | 119 | 23 | Township |
| Bloom | 7 | 2,625 | 2,703 | -0.49% | 54 | 49 | Township |
| Nile | 8 | 2,281 | 2,351 | -0.48% | 27 | 86 | Township |
| Morgan | 9 | 2,230 | 2,278 | -0.36% | 75 | 30 | Township |
| New Boston | 10 | 2,209 | 2,299 | -0.81% | 1,969 | 1 | Village |
| Union | 11 | 2,007 | 2,046 | -0.3% | 40 | 50 | Township |
| Vernon | 12 | 1,881 | 1,935 | -0.48% | 53 | 35 | Township |
| Brush Creek | 13 | 1,057 | 1,092 | -0.56% | 21 | 50 | Township |
| Rarden | 14 | 1,032 | 1,060 | -0.29% | 33 | 32 | Township |
| South Webster | 15 | 646 | 668 | -0.77% | 492 | 1 | Village |
| Rarden | 16 | 141 | 146 | -0.7% | 665 | 0 | Village |
| Otway | 17 | 88 | 93 | -1.12% | 503 | 0 | Village |
Portsmouth is the largest city in Scioto County, with a population of 17,309.
Otway is the smallest city in Scioto County, with a population of 88.
There are 17 cities in Scioto County, Ohio.