11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Columbia | 1 | 132,046 | 126,314 | 0.88% | 1,962 | 67 | City |
| Ashland | 2 | 5,264 | 4,761 | 1.94% | 845 | 6 | City |
| Centralia | 3 | 4,868 | 4,563 | 1.27% | 1,672 | 3 | City |
| Hallsville | 4 | 1,802 | 1,619 | 2.04% | 1,126 | 2 | City |
| Sturgeon | 5 | 975 | 912 | 1.25% | 1,118 | 1 | City |
| Harrisburg | 6 | 298 | 271 | 1.71% | 374 | 1 | Town |
| Rocheport | 7 | 218 | 203 | 1.4% | 688 | 0 | City |
| Hartsburg | 8 | 139 | 131 | 0.72% | 647 | 0 | Town |
| Pierpont | 9 | 64 | 62 | 0% | 281 | 0 | Village |
| Huntsdale | 10 | 30 | 28 | 0% | 100 | 0 | Town |
| McBaine | 11 | 16 | 14 | 0% | 84 | 0 | Town |
Columbia is the largest city in Boone County, with a population of 132,046.
McBaine is the smallest city in Boone County, with a population of 16.
There are 11 cities in Boone County, Missouri.