17 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Portsmouth | 1 | 17,130 | 18,207 | -1.03% | 1,597 | 11 | City |
| Porter | 2 | 9,403 | 9,782 | -0.56% | 454 | 21 | Township |
| Washington | 3 | 5,048 | 5,271 | -0.65% | 202 | 25 | Township |
| Valley | 4 | 3,511 | 3,594 | -0.51% | 142 | 25 | Township |
| Clay | 5 | 3,406 | 3,513 | -0.41% | 157 | 22 | Township |
| Rush | 6 | 2,785 | 2,887 | -0.54% | 119 | 23 | Township |
| Bloom | 7 | 2,612 | 2,703 | -0.5% | 54 | 49 | Township |
| Nile | 8 | 2,270 | 2,351 | -0.48% | 26 | 86 | Township |
| Morgan | 9 | 2,222 | 2,278 | -0.36% | 75 | 30 | Township |
| New Boston | 10 | 2,191 | 2,299 | -0.81% | 1,953 | 1 | Village |
| Union | 11 | 2,001 | 2,046 | -0.3% | 40 | 50 | Township |
| Vernon | 12 | 1,872 | 1,935 | -0.48% | 53 | 35 | Township |
| Brush Creek | 13 | 1,051 | 1,092 | -0.57% | 21 | 50 | Township |
| Rarden | 14 | 1,029 | 1,060 | -0.29% | 32 | 32 | Township |
| South Webster | 15 | 642 | 668 | -0.62% | 489 | 1 | Village |
| Rarden | 16 | 140 | 146 | -0.71% | 660 | 0 | Village |
| Otway | 17 | 87 | 93 | -1.14% | 497 | 0 | Village |
Portsmouth is the largest city in Scioto County, with a population of 17,130.
Otway is the smallest city in Scioto County, with a population of 87.
There are 17 cities in Scioto County, Ohio.