| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Columbia | 1 | 131,791 | 126,315 | 0.72% | 1,943 | 68 | City |
| Ashland | 2 | 5,313 | 4,773 | 1.76% | 853 | 6 | City |
| Centralia | 3 | 4,819 | 4,563 | 1.09% | 1,655 | 3 | City |
| Hallsville | 4 | 1,774 | 1,614 | 1.84% | 1,108 | 2 | City |
| Sturgeon | 5 | 967 | 917 | 1.04% | 1,109 | 1 | City |
| Harrisburg | 6 | 293 | 271 | 1.38% | 368 | 1 | Town |
| Rocheport | 7 | 213 | 203 | 0.95% | 672 | 0 | City |
| Hartsburg | 8 | 138 | 131 | 0.73% | 642 | 0 | Town |
| Pierpont | 9 | 68 | 64 | 0% | 298 | 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 131,791.
McBaine is the smallest city in Boone County, with a population of 16.
There are 11 cities in Boone County, Missouri.