2 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Los Alamos | 1 | 13,820 | 12,978 | 0.88% | 1,244 | 11.11 | CDP |
| White Rock | 2 | 5,559 | 5,845 | -0.2% | 787 | 7.07 | CDP |
Los Alamos is the largest city in Los Alamos County, with a population of 13,820.
White Rock is the smallest city in Los Alamos County.
There are 2 cities in Los Alamos County, New Mexico.