| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Truth or Consequences | 1 | 5,928 | 6,046 | -0.35% | 212 | 28 | City |
| Elephant Butte | 2 | 1,455 | 1,455 | -0.07% | 348 | 4 | City |
| Williamsburg | 3 | 456 | 464 | -0.44% | 938 | 0 | Village |
Truth or Consequences is the largest city in Sierra County, with a population of 5,928.
Williamsburg is the smallest city in Sierra County, with a population of 456.
There are 3 cities in Sierra County, New Mexico.