8 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Greenwood | 1 | 70,273 | 63,979 | 1.52% | 2,439 | 29 | City |
| Franklin | 2 | 26,546 | 25,382 | 0.74% | 1,685 | 16 | City |
| Bargersville | 3 | 12,065 | 9,719 | 3.35% | 645 | 19 | Town |
| New Whiteland | 4 | 5,978 | 5,569 | 1.15% | 4,114 | 1 | Town |
| Whiteland | 5 | 5,941 | 4,650 | 3.75% | 1,086 | 5 | Town |
| Edinburgh | 6 | 4,498 | 4,437 | 0.22% | 1,359 | 3 | Town |
| Trafalgar | 7 | 1,691 | 1,439 | 2.55% | 661 | 3 | Town |
| Bethany | 8 | 97 | 96 | 0% | 1,021 | 0 | Town |
Greenwood is the largest city in Johnson County, with a population of 70,273.
Bethany is the smallest city in Johnson County, with a population of 97.
There are 8 cities in Johnson County, Indiana.