8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mexico | 1 | 11,551 | 11,440 | 0.19% | 949 | 12.17 | City |
| Vandalia | 2 | 2,649 | 3,423 | -5.53% | 1,180 | 2.24 | City |
| Laddonia | 3 | 507 | 501 | 0.2% | 719 | 0.70 | City |
| Martinsburg | 4 | 260 | 252 | 0.78% | 952 | 0.27 | Town |
| Farber | 5 | 255 | 254 | 0% | 892 | 0.29 | City |
| Benton City | 6 | 106 | 103 | 0.95% | 1,019 | 0.10 | Village |
| Rush Hill | 7 | 100 | 100 | 0% | 556 | 0.18 | Village |
| Vandiver | 8 | 62 | 62 | 0% | 199 | 0.31 | Village |
Mexico is the largest city in Audrain County, with a population of 11,551.
Vandiver is the smallest city in Audrain County.
There are 8 cities in Audrain County, Missouri.