10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Truth Consequences | 1 | 5,916 | 6,045 | -0.44% | 211 | 28 | City |
| Elephant Butte | 2 | 1,435 | 1,452 | -0.28% | 343 | 4 | City |
| Williamsburg | 3 | 459 | 464 | -0.22% | 944 | 0 | Village |
| Las Palomas | 4 | 317 | 115 | 3.26% | 198 | 2 | CDP |
| Hillsboro | 5 | 188 | 199 | 2.17% | 88 | 2 | CDP |
| Kingston | 6 | 116 | 57 | 7.41% | 583 | 0 | CDP |
| Oasis | 7 | 108 | 117 | -1.82% | 52 | 2 | CDP |
| Caballo | 8 | 62 | 118 | -4.62% | 63 | 1 | CDP |
| Hot Springs Landing | 9 | 46 | 47 | -8% | 102 | 0 | CDP |
| Winston | 10 | 40 | 64 | 8.11% | 95 | 0 | CDP |
Truth Consequences is the largest city in Sierra County, with a population of 5,916.
Winston is the smallest city in Sierra County, with a population of 40.
There are 10 cities in Sierra County, New Mexico.