| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mexico | 1 | 11,576 | 11,437 | 0.16% | 951 | 12 | City |
| Vandalia | 2 | 2,901 | 3,410 | -4.23% | 1,293 | 2 | City |
| Laddonia | 3 | 509 | 501 | 0.2% | 722 | 1 | City |
| Martinsburg | 4 | 257 | 251 | 0.39% | 941 | 0 | Town |
| Farber | 5 | 254 | 255 | 0% | 888 | 0 | City |
| Benton City | 6 | 106 | 107 | -0.93% | 1,019 | 0 | Village |
| Rush Hill | 7 | 104 | 104 | 0% | 578 | 0 | Village |
| Vandiver | 8 | 64 | 64 | 0% | 205 | 0 | Village |
Mexico is the largest city in Audrain County, with a population of 11,576.
Vandiver is the smallest city in Audrain County, with a population of 64.
There are 8 cities in Audrain County, Missouri.