26 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 |
| Wheelersburg | 3 | 6,160 | 6,129 | -0.29% | 1,061 | 6 | CDP |
| Washington | 4 | 5,081 | 5,271 | -0.65% | 204 | 25 | Township |
| Valley | 5 | 3,529 | 3,594 | -0.51% | 143 | 25 | Township |
| Clay | 6 | 3,420 | 3,513 | -0.41% | 158 | 22 | Township |
| Rush | 7 | 2,800 | 2,887 | -0.53% | 119 | 23 | Township |
| Bloom | 8 | 2,625 | 2,703 | -0.49% | 54 | 49 | Township |
| West Portsmouth | 9 | 2,388 | 2,646 | -2.05% | 508 | 5 | CDP |
| Nile | 10 | 2,281 | 2,351 | -0.48% | 27 | 86 | Township |
| Morgan | 11 | 2,230 | 2,278 | -0.36% | 75 | 30 | Township |
| New Boston | 12 | 2,209 | 2,299 | -0.81% | 1,969 | 1 | Village |
| Union | 13 | 2,007 | 2,046 | -0.3% | 40 | 50 | Township |
| Rosemount | 14 | 1,988 | 2,292 | -0.4% | 346 | 6 | CDP |
| Franklin Furnace | 15 | 1,955 | 1,795 | 1.03% | 830 | 2 | CDP |
| Vernon | 16 | 1,881 | 1,935 | -0.48% | 53 | 35 | Township |
| Lucasville | 17 | 1,622 | 2,030 | -4.48% | 467 | 3 | CDP |
| Brush Creek | 18 | 1,057 | 1,092 | -0.56% | 21 | 50 | Township |
| Rarden | 19 | 1,032 | 1,060 | -0.29% | 33 | 32 | Township |
| Sciotodale | 20 | 747 | 714 | -2.99% | 387 | 2 | CDP |
| South Webster | 21 | 646 | 668 | -0.77% | 492 | 1 | Village |
| Friendship | 22 | 634 | 523 | 3.09% | 541 | 1 | CDP |
| Minford | 23 | 564 | 378 | -1.57% | 324 | 2 | CDP |
| McDermott | 24 | 553 | 354 | 1.47% | 955 | 1 | CDP |
| Rarden | 25 | 141 | 146 | -0.7% | 665 | 0 | Village |
| Otway | 26 | 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 26 cities in Scioto County, Ohio.