11 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Iowa City | 1 | 77,608 | 74,914 | 0.58% | 3,012 | 26 | City |
| Coralville | 2 | 24,770 | 22,336 | 1.67% | 1,955 | 13 | City |
| North Liberty | 3 | 22,604 | 20,503 | 1.57% | 2,372 | 10 | City |
| Tiffin | 4 | 7,730 | 4,624 | 7.18% | 1,810 | 4 | City |
| Solon | 5 | 3,405 | 3,041 | 1.82% | 2,131 | 2 | City |
| Lone Tree | 6 | 1,336 | 1,350 | -0.15% | 1,252 | 1 | City |
| University Heights | 7 | 1,170 | 1,223 | -0.76% | 4,500 | 0 | City |
| Hills | 8 | 935 | 862 | 1.3% | 1,137 | 1 | City |
| Swisher | 9 | 905 | 916 | -0.22% | 969 | 1 | City |
| Shueyville | 10 | 722 | 730 | -0.14% | 387 | 2 | City |
| Oxford | 11 | 714 | 716 | 0% | 772 | 1 | City |
Iowa City is the largest city in Johnson County, with a population of 77,608.
Oxford is the smallest city in Johnson County, with a population of 714.
There are 11 cities in Johnson County, Iowa.