Population of Counties in New Mexico (2021)

New Mexico has 33 counties. The most populous county in New Mexico is Bernalillo County, which has 678,701 residents. Bernalillo County is home to Albuquerque, the most populous city in the state and the state’s primary economic and business hub. The second-most populous county in New Mexico is Doña Ana County, which has 217,522 people, followed by Santa Fe County, which is home to the state capital of Santa Fe and has a population of 150,056. All three counties have grown since the 2010 Census, by 2.22%, 3.53%, 3.82% respectively.

New Mexico Counties with the Fewest Residents

Of New Mexico’s 33 counties, Harding County has the fewest residents with just 655. This results in a population density of 0.31 persons per square kilometer. About 0.03% of New Mexico’s total population lives in Harding County. De Baca County has the second smallest population of 1,781 people, about 0.08% of the total population. The population density in De Baca County is still less than one person per square kilometer at 0.77 persons. Catron County is the third-least populous county in New Mexico, with a population of 3,578 people. Catron County’s population comprises 0.17% of the state’s total population and its density is 0.52 persons per square kilometer.

New Mexico Counties with Rapid Growth

None of New Mexico’s counties have experienced double-digit growth since 2010. The county that has experienced the highest population growth is Sandoval County, which grew by 9.63%. This is followed by Lea County (7.76%) and Eddy County (7.42%).

The majority of New Mexico counties have experienced population loss since the 2010 Census. Hidalgo County has experienced the greatest population loss of 12.83%, followed by De Baca County (12.22%) and Colfax County (11.82%).

Name 2021 Population Growth Since 2010 Density (mi²)
Bernalillo County681,2952.62%320.54
Doña Ana County220,0294.73%103.52
Santa Fe County151,5524.86%71.30
Sandoval County150,05213.31%70.60
San Juan County120,876-7.16%56.87
Valencia County77,4540.85%36.44
Lea County74,12414.75%34.87
McKinley County70,279-1.94%33.07
Otero County69,1527.37%32.53
Chaves County64,737-1.50%30.46
Eddy County59,92211.15%28.19
Curry County48,186-1.60%22.67
Rio Arriba County38,717-3.89%18.22
Taos County32,771-0.38%15.42
San Miguel County26,871-8.58%12.64
Cibola County26,493-3.01%12.46
Grant County26,388-10.19%12.42
Luna County23,373-6.81%11.00
Los Alamos County20,13111.88%9.47
Lincoln County19,680-3.77%9.26
Roosevelt County17,982-10.17%8.46
Socorro County16,503-7.24%7.76
Torrance County15,359-6.37%7.23
Colfax County11,681-14.89%5.50
Sierra County10,475-13.01%4.93
Quay County8,275-8.70%3.89
Mora County4,589-6.21%2.16
Guadalupe County4,232-9.86%1.99
Hidalgo County4,132-15.05%1.94
Union County3,961-12.77%1.86
Catron County3,473-7.34%1.63
De Baca County1,686-16.99%0.79
Harding County575-16.67%0.27