34 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Greenwood | 1 | 67,839 | 63,981 | 1.15% | 2,412 | 28.12 | City |
| Pleasant township | 2 | 67,171 | 62,223 | 1.61% | 1,906 | 35.23 | Township |
| Franklin township | 3 | 65,674 | 66,241 | -0.07% | 1,557 | 42.18 | Township |
| White River township | 4 | 55,902 | 52,585 | 1.25% | 1,187 | 47.09 | Township |
| Franklin | 5 | 26,264 | 25,374 | 0.68% | 1,716 | 15.30 | City |
| Franklin township | 6 | 21,974 | 21,262 | 0.7% | 619 | 35.50 | Township |
| Bargersville | 7 | 11,979 | 9,719 | 3.92% | 640 | 18.71 | Town |
| Needham township | 8 | 7,840 | 7,603 | 0.69% | 224 | 35.02 | Township |
| Franklin township | 9 | 7,078 | 7,044 | 0.4% | 196 | 36.06 | Township |
| Whiteland | 10 | 5,925 | 4,649 | 4.5% | 1,083 | 5.47 | Town |
| New Whiteland | 11 | 5,908 | 5,570 | 1.16% | 4,066 | 1.45 | Town |
| Blue River township | 12 | 4,879 | 4,825 | 0.68% | 201 | 24.29 | Township |
| Edinburgh | 13 | 4,421 | 4,440 | -0.09% | 1,423 | 3.11 | Town |
| Nineveh township | 14 | 4,245 | 4,197 | 0.4% | 117 | 36.22 | Township |
| Franklin township | 15 | 4,214 | 4,157 | 0.43% | 122 | 34.41 | Township |
| Hensley township | 16 | 4,063 | 3,798 | 1.55% | 111 | 36.50 | Township |
| Franklin township | 17 | 3,710 | 3,631 | 0.68% | 102 | 36.55 | Township |
| Union township | 18 | 3,029 | 2,831 | 1.3% | 84 | 36.15 | Township |
| Clark township | 19 | 2,982 | 2,913 | 0.64% | 87 | 34.43 | Township |
| Franklin township | 20 | 2,482 | 2,455 | 0.32% | 56 | 44.25 | Township |
| Franklin township | 21 | 1,819 | 1,766 | 0.72% | 47 | 38.93 | Township |
| Franklin township | 22 | 1,696 | 1,618 | 0.95% | 49 | 34.39 | Township |
| Trafalgar | 23 | 1,648 | 1,435 | 2.68% | 644 | 2.56 | Town |
| Franklin township | 24 | 1,608 | 1,533 | 1.07% | 68 | 23.52 | Township |
| Franklin township | 25 | 1,317 | 1,323 | 0% | 46 | 28.36 | Township |
| Franklin township | 26 | 1,297 | 1,258 | 0.46% | 49 | 26.34 | Township |
| Franklin township | 27 | 1,276 | 1,258 | 0.16% | 36 | 35.09 | Township |
| Franklin township | 28 | 1,183 | 1,151 | 0.6% | 34 | 35.12 | Township |
| Franklin township | 29 | 1,100 | 1,095 | 0.18% | 39 | 28.46 | Township |
| Franklin township | 30 | 1,096 | 1,109 | -0.36% | 46 | 23.93 | Township |
| Painted Hills | 31 | 1,076 | 525 | 2.57% | 622 | 1.73 | CDP |
| Franklin township | 32 | 1,072 | 1,085 | -0.46% | 31 | 34.21 | Township |
| Franklin township | 33 | 714 | 718 | -0.14% | 20 | 36.38 | Township |
| Bethany | 34 | 95 | 94 | 0% | 1,000 | 0.10 | Town |
Greenwood is the largest city in Johnson County, with a population of 67,839.
Bethany is the smallest city in Johnson County.
There are 34 cities in Johnson County, Indiana.