The county has two census-designated places: Los Alamos and White Rock.

The county's highest point is located along its northern border, near the summit of Caballo Mountain, at 10,480 feet (3,190 m) above sea level.

The council consists of seven members elected at large for four-year, staggered terms.

[15] In a study conducted by American City Business Journals in 2004, Los Alamos County topped the list as the best place to live in the United States in terms of quality of life.

This was attributed to the high levels of job stability, income and education of Los Alamos residents, many of whom are employed as scientists and engineers at the Los Alamos National Laboratory.

In per capita income, Los Alamos County ranks 1st in New Mexico and 7th in the United States, and has the second-lowest level of poverty in the United States, and the lowest level of child poverty.

[3] Other factors contributing to Los Alamos's high quality-of-life index were the access to affordable housing and short commuting times.

[19] Both Los Alamos County and the Los Alamos National Laboratory are trying to reduce their respective carbon emissions[19] in order to help mitigate the continually worsening dangers of climate change.

[22] The Project planned to use NuScale Power’s Small Module Reactor design to provide nuclear energy to counties across the United States, but was cancelled in 2023 because of cost increases.

[23] Los Alamos’ history is tied to nuclear energy, which has an environmental impact comparable to that of renewables as a source of domestic power.

In 2024, Democratic nominee Kamala Harris won the highest percentage of the vote in the county since 1964.

Los Alamos County had the highest percentage of support for Gary Johnson in New Mexico in the 2016 election, at 13.89% (a total of 1,512 votes out of 10,885 cast).