11 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Columbia | 1 | 133,193 | 126,314 | 0.87% | 1,963 | 68 | City |
| Ashland | 2 | 5,365 | 4,761 | 1.92% | 862 | 6 | City |
| Centralia | 3 | 4,929 | 4,563 | 1.25% | 1,693 | 3 | City |
| Hallsville | 4 | 1,839 | 1,619 | 2.05% | 1,149 | 2 | City |
| Sturgeon | 5 | 988 | 912 | 1.33% | 1,133 | 1 | City |
| Harrisburg | 6 | 304 | 271 | 2.01% | 382 | 1 | Town |
| Rocheport | 7 | 221 | 203 | 1.38% | 697 | 0 | City |
| Hartsburg | 8 | 141 | 131 | 1.44% | 656 | 0 | Town |
| Pierpont | 9 | 65 | 62 | 1.56% | 285 | 0 | Village |
| Huntsdale | 10 | 31 | 28 | 3.33% | 104 | 0 | Town |
| McBaine | 11 | 17 | 14 | 6.25% | 89 | 0 | Town |
Columbia is the largest city in Boone County, with a population of 133,193.
McBaine is the smallest city in Boone County, with a population of 17.
There are 11 cities in Boone County, Missouri.