5 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lebanon | 1 | 6,669 | 6,289 | 1.15% | 976 | 6.83 | City |
| Loretto | 2 | 712 | 717 | -0.14% | 223 | 3.19 | City |
| Bradfordsville | 3 | 275 | 269 | 0.36% | 1,019 | 0.27 | City |
| Raywick | 4 | 155 | 154 | 0% | 173 | 0.90 | City |
| St. Mary | 5 | 146 | 138 | 1.39% | 188 | 0.78 | City |
Lebanon is the largest city in Marion County, with a population of 6,669.
St. Mary is the smallest city in Marion County.
There are 5 cities in Marion County, Kentucky.