| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lebanon | 1 | 6,777 | 6,294 | 1.16% | 992 | 7 | City |
| Loretto | 2 | 713 | 716 | -0.14% | 224 | 3 | City |
| Bradfordsville | 3 | 285 | 273 | 0.71% | 1,056 | 0 | City |
| Raywick | 4 | 155 | 154 | 0% | 173 | 1 | City |
| St. Mary | 5 | 137 | 139 | -0.72% | 176 | 1 | City |
Lebanon is the largest city in Marion County, with a population of 6,777.
St. Mary is the smallest city in Marion County, with a population of 137.
There are 5 cities in Marion County, Kentucky.