Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Los Alamos | 1 | 13,700 | 12,978 | 0.88% | 1,233 | 11.1 | CDP |
| White Rock | 2 | 5,570 | 5,845 | -0.2% | 788 | 7.1 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Los Alamos is the largest city in Los Alamos County.
White Rock is the smallest city in Los Alamos County.
There are 2 cities in Los Alamos County, New Mexico.