29 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Steubenville | 1 | 17,969 | 18,149 | -0.17% | 1,705 | 11 | City |
| Island Creek | 2 | 9,936 | 10,244 | -0.34% | 238 | 42 | Township |
| Cross Creek | 3 | 7,582 | 7,837 | -0.35% | 242 | 31 | Township |
| Toronto | 4 | 5,130 | 5,300 | -0.54% | 2,459 | 2 | City |
| Knox | 5 | 4,201 | 4,310 | -0.26% | 144 | 29 | Township |
| Steubenville | 6 | 3,957 | 4,102 | -0.4% | 528 | 7 | Township |
| Wintersville | 7 | 3,624 | 3,768 | -0.66% | 1,160 | 3 | Village |
| Mingo Junction | 8 | 3,204 | 3,342 | -0.71% | 1,191 | 3 | Village |
| Smithfield | 9 | 2,910 | 3,002 | -0.31% | 77 | 38 | Township |
| Wells | 10 | 2,374 | 2,446 | -0.29% | 89 | 27 | Township |
| Mount Pleasant | 11 | 2,143 | 2,225 | -0.42% | 112 | 19 | Township |
| Tiltonsville | 12 | 1,202 | 1,255 | -0.74% | 2,294 | 1 | Village |
| Saline | 13 | 1,121 | 1,159 | -0.44% | 53 | 21 | Township |
| Richmond | 14 | 994 | 1,011 | -0.3% | 39 | 25 | Township |
| Richmond | 15 | 940 | 970 | -0.53% | 37 | 25 | Township |
| Yorkville | 16 | 922 | 966 | -0.75% | 1,557 | 1 | Village |
| Adena | 17 | 638 | 667 | -0.78% | 1,188 | 1 | Village |
| Dillonvale | 18 | 588 | 615 | -0.68% | 1,523 | 0 | Village |
| Bergholz | 19 | 515 | 542 | -0.77% | 915 | 1 | Village |
| Amsterdam | 20 | 419 | 437 | -0.71% | 1,309 | 0 | Village |
| Richmond | 21 | 395 | 412 | -0.75% | 714 | 1 | Village |
| Brush Creek | 22 | 382 | 392 | 0% | 16 | 24 | Township |
| Rayland | 23 | 376 | 393 | -0.79% | 795 | 0 | Village |
| Mount Pleasant | 24 | 374 | 392 | -0.8% | 1,467 | 0 | Village |
| Irondale | 25 | 313 | 327 | -0.63% | 216 | 1 | Village |
| Stratton | 26 | 259 | 265 | -0.38% | 482 | 1 | Village |
| Empire | 27 | 225 | 230 | -0.44% | 750 | 0 | Village |
| New Alexandria | 28 | 221 | 232 | -0.9% | 602 | 0 | Village |
| Bloomingdale | 29 | 132 | 140 | -0.75% | 1,500 | 0 | Village |
Steubenville is the largest city in Jefferson County, with a population of 17,969.
Bloomingdale is the smallest city in Jefferson County, with a population of 132.
There are 29 cities in Jefferson County, Ohio.