22 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Columbia | 1 | 132,046 | 126,055 | 0.88% | 1,962 | 67 | City |
| Columbia | 2 | 132,046 | 126,314 | 0.88% | 1,962 | 67 | City |
| Ashland | 3 | 5,264 | 4,746 | 1.94% | 845 | 6 | City |
| Ashland | 4 | 5,264 | 4,761 | 1.94% | 845 | 6 | City |
| Centralia | 5 | 4,868 | 4,549 | 1.27% | 1,672 | 3 | City |
| Centralia | 6 | 4,868 | 4,563 | 1.27% | 1,672 | 3 | City |
| Hallsville | 7 | 1,802 | 1,614 | 2.04% | 1,126 | 2 | City |
| Hallsville | 8 | 1,802 | 1,619 | 2.04% | 1,126 | 2 | City |
| Sturgeon | 9 | 975 | 910 | 1.25% | 1,118 | 1 | City |
| Sturgeon | 10 | 975 | 912 | 1.25% | 1,118 | 1 | City |
| Harrisburg | 11 | 298 | 269 | 1.71% | 374 | 1 | Town |
| Harrisburg | 12 | 298 | 271 | 1.71% | 374 | 1 | Town |
| Rocheport | 13 | 218 | 203 | 1.4% | 688 | 0 | City |
| Rocheport | 14 | 218 | 203 | 1.4% | 688 | 0 | City |
| Hartsburg | 15 | 139 | 131 | 0.72% | 647 | 0 | Town |
| Hartsburg | 16 | 139 | 131 | 0.72% | 647 | 0 | Town |
| Pierpont | 17 | 64 | 62 | 0% | 281 | 0 | Village |
| Pierpont | 18 | 64 | 62 | 0% | 281 | 0 | Village |
| Huntsdale | 19 | 30 | 28 | 0% | 100 | 0 | Town |
| Huntsdale | 20 | 30 | 28 | 0% | 100 | 0 | Town |
| McBaine | 21 | 16 | 14 | 0% | 84 | 0 | Town |
| McBaine | 22 | 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 22 cities in Boone County, Missouri.