8 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Tishomingo | 1 | 3,075 | 3,098 | -0.13% | 583 | 5 | City |
| Mannsville | 2 | 741 | 725 | 0.41% | 244 | 3 | Town |
| Ravia | 3 | 468 | 464 | 0.21% | 800 | 1 | Town |
| Wapanucka | 4 | 392 | 386 | 0.26% | 603 | 1 | Town |
| Mill Creek | 5 | 291 | 290 | 0% | 758 | 0 | Town |
| Milburn | 6 | 250 | 249 | 0% | 533 | 0 | Town |
| Kenefic | 7 | 164 | 148 | 1.86% | 165 | 1 | Town |
| Bromide | 8 | 121 | 120 | 0% | 180 | 1 | Town |
Tishomingo is the largest city in Johnston County, with a population of 3,075.
Bromide is the smallest city in Johnston County, with a population of 121.
There are 8 cities in Johnston County, Oklahoma.