4 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Warrenton | 1 | 9,785 | 8,567 | 2.56% | 1,082 | 9.05 | City |
| Wright City | 2 | 5,682 | 4,862 | 2.97% | 938 | 6.06 | City |
| Marthasville | 3 | 1,309 | 1,244 | 1% | 1,533 | 0.85 | City |
| Truesdale | 4 | 965 | 860 | 2.23% | 753 | 1.28 | City |
Warrenton is the largest city in Warren County, with a population of 9,785.
Truesdale is the smallest city in Warren County.
There are 4 cities in Warren County, Missouri.