4 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Rolla | 1 | 21,029 | 19,921 | 0.89% | 1,734 | 12 | City |
| St. James | 2 | 3,941 | 3,913 | 0.13% | 923 | 4 | City |
| Newburg | 3 | 337 | 333 | 0.3% | 522 | 1 | City |
| Edgar Springs | 4 | 204 | 200 | 0.49% | 435 | 0 | City |
Rolla is the largest city in Phelps County, with a population of 21,029.
Edgar Springs is the smallest city in Phelps County, with a population of 204.
There are 4 cities in Phelps County, Missouri.