34 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Greenwood | 1 | 69,224 | 63,979 | 1.54% | 2,462 | 28 | City |
| Pleasant | 2 | 68,174 | 62,210 | 2.24% | 1,935 | 35 | Township |
| Franklin | 3 | 67,194 | 66,246 | 0.7% | 1,593 | 42 | Township |
| White River | 4 | 55,818 | 52,608 | 1.01% | 1,185 | 47 | Township |
| Franklin | 5 | 26,352 | 25,382 | 0.74% | 1,722 | 15 | City |
| Franklin | 6 | 21,980 | 21,266 | 0.57% | 619 | 36 | Township |
| Bargersville | 7 | 11,674 | 9,719 | 3.47% | 624 | 19 | Town |
| Needham | 8 | 7,839 | 7,603 | 0.54% | 224 | 35 | Township |
| Franklin | 9 | 7,091 | 7,045 | 0.34% | 197 | 36 | Township |
| New Whiteland | 10 | 5,910 | 5,569 | 1.16% | 4,067 | 1 | Town |
| Whiteland | 11 | 5,726 | 4,650 | 3.9% | 1,046 | 5 | Town |
| Blue River | 12 | 4,870 | 4,827 | 0.43% | 201 | 24 | Township |
| Edinburgh | 13 | 4,488 | 4,437 | 0.22% | 1,445 | 3 | Town |
| Nineveh | 14 | 4,222 | 4,197 | -0.05% | 117 | 36 | Township |
| Franklin | 15 | 4,171 | 4,158 | -0.14% | 121 | 34 | Township |
| Hensley | 16 | 4,032 | 3,807 | 0.9% | 110 | 37 | Township |
| Franklin | 17 | 3,653 | 3,634 | 0.05% | 100 | 37 | Township |
| Clark | 18 | 2,997 | 2,916 | 0.67% | 87 | 34 | Township |
| Union | 19 | 2,991 | 2,829 | 0.54% | 83 | 36 | Township |
| Franklin | 20 | 2,498 | 2,456 | 0.73% | 56 | 44 | Township |
| Franklin | 21 | 1,799 | 1,764 | 0.22% | 46 | 39 | Township |
| Franklin | 22 | 1,695 | 1,620 | 0.71% | 49 | 34 | Township |
| Trafalgar | 23 | 1,649 | 1,439 | 2.61% | 644 | 3 | Town |
| Franklin | 24 | 1,645 | 1,535 | 2.05% | 70 | 24 | Township |
| Franklin | 25 | 1,333 | 1,325 | 0.38% | 47 | 28 | Township |
| Franklin | 26 | 1,300 | 1,258 | 0.39% | 49 | 26 | Township |
| Franklin | 27 | 1,292 | 1,258 | 0.23% | 37 | 35 | Township |
| Franklin | 28 | 1,172 | 1,146 | 0.26% | 33 | 35 | Township |
| Franklin | 29 | 1,110 | 1,109 | 0.09% | 46 | 24 | Township |
| Franklin | 30 | 1,104 | 1,097 | 0.18% | 39 | 28 | Township |
| Franklin | 31 | 1,094 | 1,089 | 0.37% | 32 | 34 | Township |
| Painted Hills | 32 | 1,076 | 525 | 2.57% | 622 | 2 | CDP |
| Franklin | 33 | 718 | 718 | 0.14% | 20 | 36 | Township |
| Bethany | 34 | 97 | 96 | 0% | 1,021 | 0 | Town |
Greenwood is the largest city in Johnson County, with a population of 69,224.
Bethany is the smallest city in Johnson County, with a population of 97.
There are 34 cities in Johnson County, Indiana.