| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Clarksville | 1 | 9,702 | 9,361 | 0.73% | 533 | 18 | City |
| Lamar | 2 | 1,789 | 1,720 | 0.73% | 388 | 5 | City |
| Coal Hill | 3 | 823 | 813 | 0.12% | 294 | 3 | City |
| Knoxville | 4 | 665 | 651 | 0.45% | 209 | 3 | Town |
| Hartman | 5 | 519 | 514 | 0.19% | 328 | 2 | City |
Clarksville is the largest city in Johnson County, with a population of 9,702.
Hartman is the smallest city in Johnson County, with a population of 519.
There are 5 cities in Johnson County, Arkansas.