4 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Brookville | 1 | 2,671 | 2,623 | 0.3% | 1,912 | 1 | Town |
| Oldenburg | 2 | 649 | 642 | 0.15% | 1,509 | 0 | Town |
| Laurel | 3 | 413 | 409 | 0.24% | 1,735 | 0 | Town |
| Cedar Grove | 4 | 146 | 146 | 0% | 967 | 0 | Town |
Brookville is the largest city in Franklin County, with a population of 2,671.
Cedar Grove is the smallest city in Franklin County, with a population of 146.
There are 4 cities in Franklin County, Indiana.