8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mexico | 1 | 11,493 | 11,438 | 0.1% | 944 | 12 | City |
| Vandalia | 2 | 2,818 | 3,420 | -4.12% | 1,256 | 2 | City |
| Laddonia | 3 | 508 | 501 | 0.2% | 721 | 1 | City |
| Martinsburg | 4 | 258 | 251 | 0.39% | 945 | 0 | Town |
| Farber | 5 | 252 | 255 | -0.4% | 881 | 0 | City |
| Benton City | 6 | 102 | 104 | -0.97% | 981 | 0 | Village |
| Rush Hill | 7 | 97 | 99 | -1.02% | 539 | 0 | Village |
| Vandiver | 8 | 63 | 63 | 0% | 202 | 0 | Village |
Mexico is the largest city in Audrain County, with a population of 11,493.
Vandiver is the smallest city in Audrain County, with a population of 63.
There are 8 cities in Audrain County, Missouri.