New Mexico Counties by Population (2025)
Top 5 Most Populous Counties
33 Counties
| County | 2025 Pop. ↓ | Area (mi²) | Density | Change (2020) |
|---|---|---|---|---|
| Bernalillo County | 668,844 | 1,161 | 576 | -1.18% |
| Doña Ana County | 228,570 | 3,808 | 60 | 3.87% |
| Sandoval County | 160,614 | 3,710 | 43 | 7.59% |
| Santa Fe County | 156,346 | 1,910 | 82 | 0.84% |
| San Juan County | 120,887 | 5,517 | 22 | -0.4% |
| Valencia County | 81,021 | 1,067 | 76 | 6.08% |
| Lea County | 71,617 | 4,392 | 16 | -4.05% |
| Otero County | 69,471 | 6,613 | 11 | 2.37% |
| McKinley County | 66,529 | 5,451 | 12 | -8.35% |
| Chaves County | 62,899 | 6,067 | 10 | -3.45% |
| Eddy County | 60,419 | 4,176 | 14 | -3.07% |
| Curry County | 46,806 | 1,406 | 33 | -3.23% |
| Rio Arriba County | 39,646 | 5,861 | 7 | -1.55% |
| Taos County | 34,035 | 2,202 | 15 | -1.24% |
| Grant County | 27,030 | 3,961 | 7 | -4.17% |
| Cibola County | 26,598 | 4,540 | 6 | -1.86% |
| San Miguel County | 26,200 | 4,722 | 6 | -3.43% |
| Luna County | 24,562 | 2,965 | 8 | -3.52% |
| Los Alamos County | 19,786 | 109 | 182 | 1.9% |
| Lincoln County | 19,401 | 4,831 | 4 | -4.46% |
| Roosevelt County | 18,645 | 2,446 | 8 | -2.63% |
| Torrance County | 16,133 | 3,345 | 5 | 7.11% |
| Socorro County | 15,667 | 6,646 | 2 | -5.34% |
| Colfax County | 12,221 | 3,758 | 3 | -1.06% |
| Sierra County | 11,516 | 4,181 | 3 | -0.4% |
| Quay County | 8,472 | 2,874 | 3 | -2.75% |
| Guadalupe County | 4,244 | 3,030 | 1 | -4.39% |
| Mora County | 4,075 | 1,926 | 2 | -2.77% |
| Union County | 3,928 | 3,825 | 1 | -3.51% |
| Catron County | 3,889 | 6,924 | 1 | 7.85% |
| Hidalgo County | 3,873 | 3,439 | 1 | -6.99% |
| De Baca County | 1,587 | 2,323 | 1 | -5.59% |
| Harding County | 630 | 2,125 | 0.30 | -3.52% |
Overview of New Mexico Counties
There are 33 counties in New Mexico.
Bernalillo County is the largest county in the state, with a population of 668,844. The most recent census shows that its population has decreased by 0.01% since the previous census.
A number of other New Mexico counties also boast relatively large populations for their state, though not able to match the density of Bernalillo County:
- Doña Ana County : 228,570
- Sandoval County : 160,614
New Mexico Counties with the Fewest Residents
The smallest county in New Mexico is Harding County, with a population of just 630. This total represents a decrease of 0.0% since the last census count was performed.
Other small counties include:
- De Baca County : 1,587
- Hidalgo County : 3,873
- Catron County : 3,889
New Mexico Counties with Rapid Growth
Catron County, with its current population of 3,889, has shown the largest population growth, with an increase of 0.1% since the last census.
Bernalillo County has also had relatively high population growth of -0.01% with 668,844 residents.
On the other hand, McKinley County has had the largest decrease in population, with its 66,529 current residents totalling 0.1% less than the previous census.
Sources
- US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
- US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
- American Community Survey (2009 - 2013)
- Census QuickFacts
- Historical Populations of States and Counties (1790 - 1990)