| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Marble Hill | 1 | 1,379 | 1,374 | -0.07% | 834 | 2 | City |
| Sedgewickville | 2 | 192 | 191 | 0% | 300 | 1 | Village |
| Longtown | 3 | 92 | 91 | 0% | 736 | 0 | Town |
| Glen Allen | 4 | 66 | 64 | 0% | 1,138 | 0 | Town |
Marble Hill is the largest city in Bollinger County, with a population of 1,379.
Glen Allen is the smallest city in Bollinger County, with a population of 66.
There are 4 cities in Bollinger County, Missouri.