| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Tishomingo | 1 | 3,121 | 3,099 | -0.06% | 592 | 5 | City |
| Mannsville | 2 | 757 | 725 | 0.53% | 249 | 3 | Town |
| Ravia | 3 | 472 | 463 | 0% | 807 | 1 | Town |
| Wapanucka | 4 | 398 | 386 | 0.25% | 612 | 1 | Town |
| Mill Creek | 5 | 296 | 291 | 0% | 771 | 0 | Town |
| Milburn | 6 | 253 | 249 | 0% | 539 | 0 | Town |
| Kenefic | 7 | 164 | 148 | 1.86% | 165 | 1 | Town |
| Bromide | 8 | 121 | 119 | 0% | 180 | 1 | Town |
Tishomingo is the largest city in Johnston County, with a population of 3,121.
Bromide is the smallest city in Johnston County, with a population of 121.
There are 8 cities in Johnston County, Oklahoma.