4 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Vega | 1 | 919 | 879 | 0.88% | 687 | 1 | City |
| Wildorado | 2 | 246 | 150 | 6.96% | 105 | 2 | CDP |
| Adrian | 3 | 136 | 129 | 0.74% | 289 | 0 | City |
| Boys Ranch | 4 | 87 | 250 | -13% | 54 | 2 | CDP |
Vega is the largest city in Oldham County, with a population of 919.
Boys Ranch is the smallest city in Oldham County, with a population of 87.
There are 4 cities in Oldham County, Texas.