6 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Clarksville | 1 | 9,665 | 9,367 | 0.61% | 531 | 18 | City |
| Lamar | 2 | 1,781 | 1,718 | 0.68% | 386 | 5 | City |
| Coal Hill | 3 | 814 | 813 | 0% | 290 | 3 | City |
| Knoxville | 4 | 667 | 651 | 0.45% | 209 | 3 | Town |
| Hartman | 5 | 514 | 512 | 0% | 325 | 2 | City |
| Hagarville | 6 | 73 | 24 | -3.95% | 18 | 4 | CDP |
Clarksville is the largest city in Johnson County, with a population of 9,665.
Hagarville is the smallest city in Johnson County, with a population of 73.
There are 6 cities in Johnson County, Arkansas.