12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Duncan | 1 | 23,304 | 22,675 | 0.56% | 543 | 43 | City |
| Duncan | 2 | 23,304 | 22,653 | 0.56% | 543 | 43 | City |
| Marlow | 3 | 4,534 | 4,390 | 0.64% | 643 | 7 | City |
| Marlow | 4 | 4,534 | 4,388 | 0.64% | 643 | 7 | City |
| Comanche | 5 | 1,403 | 1,372 | 0.43% | 331 | 4 | City |
| Comanche | 6 | 1,403 | 1,371 | 0.43% | 331 | 4 | City |
| Velma | 7 | 578 | 558 | 0.7% | 427 | 1 | Town |
| Velma | 8 | 578 | 558 | 0.7% | 427 | 1 | Town |
| Foster | 9 | 250 | 245 | 0.4% | 7 | 34 | Town |
| Foster | 10 | 250 | 245 | 0.4% | 7 | 34 | Town |
| Loco | 11 | 107 | 101 | 0.94% | 408 | 0 | Town |
| Loco | 12 | 107 | 101 | 0.94% | 408 | 0 | Town |
Duncan is the largest city in Stephens County, with a population of 23,304.
Loco is the smallest city in Stephens County, with a population of 107.
There are 12 cities in Stephens County, Oklahoma.