33 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 |
| Pleasant | 2 | 69,668 | 62,210 | 2.19% | 1,977 | 35 | Township |
| Franklin | 3 | 67,664 | 66,246 | 0.7% | 1,604 | 42 | Township |
| White River | 4 | 56,375 | 52,608 | 1% | 1,197 | 47 | Township |
| Franklin | 5 | 26,546 | 25,382 | 0.74% | 1,685 | 16 | City |
| Franklin | 6 | 22,105 | 21,266 | 0.57% | 623 | 36 | Township |
| Bargersville | 7 | 12,065 | 9,719 | 3.35% | 645 | 19 | Town |
| Needham | 8 | 7,881 | 7,603 | 0.54% | 225 | 35 | Township |
| Franklin | 9 | 7,115 | 7,045 | 0.34% | 197 | 36 | Township |
| New Whiteland | 10 | 5,978 | 5,569 | 1.15% | 4,114 | 1 | Town |
| Whiteland | 11 | 5,941 | 4,650 | 3.75% | 1,086 | 5 | Town |
| Blue River | 12 | 4,891 | 4,827 | 0.43% | 201 | 24 | Township |
| Edinburgh | 13 | 4,498 | 4,437 | 0.22% | 1,359 | 3 | Town |
| Nineveh | 14 | 4,220 | 4,197 | -0.05% | 117 | 36 | Township |
| Franklin | 15 | 4,165 | 4,158 | -0.14% | 121 | 34 | Township |
| Hensley | 16 | 4,068 | 3,807 | 0.89% | 111 | 37 | Township |
| Franklin | 17 | 3,655 | 3,634 | 0.05% | 100 | 37 | Township |
| Clark | 18 | 3,017 | 2,916 | 0.67% | 88 | 34 | Township |
| Union | 19 | 3,007 | 2,829 | 0.53% | 83 | 36 | Township |
| Franklin | 20 | 2,516 | 2,456 | 0.72% | 57 | 44 | Township |
| Franklin | 21 | 1,803 | 1,764 | 0.22% | 46 | 39 | Township |
| Franklin | 22 | 1,707 | 1,620 | 0.71% | 50 | 34 | Township |
| Trafalgar | 23 | 1,691 | 1,439 | 2.55% | 661 | 3 | Town |
| Franklin | 24 | 1,678 | 1,535 | 2.01% | 71 | 24 | Township |
| Franklin | 25 | 1,338 | 1,325 | 0.38% | 47 | 28 | Township |
| Franklin | 26 | 1,305 | 1,258 | 0.38% | 50 | 26 | Township |
| Franklin | 27 | 1,295 | 1,258 | 0.23% | 37 | 35 | Township |
| Franklin | 28 | 1,175 | 1,146 | 0.26% | 33 | 35 | Township |
| Franklin | 29 | 1,111 | 1,109 | 0.09% | 46 | 24 | Township |
| Franklin | 30 | 1,106 | 1,097 | 0.18% | 39 | 28 | Township |
| Franklin | 31 | 1,098 | 1,089 | 0.37% | 32 | 34 | Township |
| Franklin | 32 | 719 | 718 | 0.14% | 20 | 36 | Township |
| Bethany | 33 | 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 33 cities in Johnson County, Indiana.