What are the largest counties in New Mexico?
Bernalillo County is the largest county in New Mexico, with 667,601 residents in 2025 (Census PEP). Doña Ana County (229,091) and Sandoval County (159,565) come next.
Data as of 2025 · updated
All 32 ranked New Mexico counties
| Rank | County | Residents 2025 | Change 2020–25 |
|---|---|---|---|
| 1 | Bernalillo County | 667,601 | −1.4% |
| 2 | Doña Ana County | 229,091 | +4.1% |
| 3 | Sandoval County | 159,565 | +6.9% |
| 4 | Santa Fe County | 156,907 | +1.2% |
| 5 | San Juan County | 120,340 | −0.9% |
| 6 | Valencia County | 82,013 | +7.2% |
| 7 | Lea County | 74,749 | +0.2% |
| 8 | Otero County | 70,368 | +3.7% |
| 9 | McKinley County | 68,119 | −6.1% |
| 10 | Chaves County | 63,364 | −2.7% |
| 11 | Eddy County | 62,509 | +0.3% |
| 12 | Curry County | 46,655 | −3.5% |
| 13 | Rio Arriba County | 39,832 | −1.0% |
| 14 | Taos County | 34,564 | +0.3% |
| 15 | Grant County | 27,252 | −3.4% |
| 16 | Cibola County | 26,807 | −0.6% |
| 17 | San Miguel County | 26,260 | −3.2% |
| 18 | Luna County | 25,407 | −0.2% |
| 19 | Lincoln County | 19,844 | −2.3% |
| 20 | Los Alamos County | 19,407 | −0.0% |
| 21 | Roosevelt County | 18,615 | −2.8% |
| 22 | Torrance County | 16,100 | +6.9% |
| 23 | Socorro County | 15,838 | −4.3% |
| 24 | Colfax County | 12,184 | −1.4% |
| 25 | Sierra County | 11,395 | −1.4% |
| 26 | Quay County | 8,454 | −3.0% |
| 27 | Guadalupe County | 4,343 | −2.2% |
| 28 | Mora County | 4,051 | −3.3% |
| 29 | Hidalgo County | 3,929 | −5.6% |
| 30 | Union County | 3,844 | −5.6% |
| 31 | Catron County | 3,827 | +6.1% |
| 32 | De Baca County | 1,647 | −2.4% |
How this is ranked
The Census Bureau's July 1 resident population estimates for 2025, largest first, with the change since 2020. Counties with fewer than 1,000 residents are not ranked. Areas without an estimate for the same year as the others are not ranked.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2025). Figures come from public federal statistics and are informational only, not investment advice. Check the source before relying on a number. Methodology: how ranks and figures are built.
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Questions
What is the largest county in New Mexico?
Bernalillo County is the largest county in New Mexico, with 667,601 residents in 2025 (Census PEP). Doña Ana County (229,091) and Sandoval County (159,565) come next.
How is this ranking calculated?
The Census Bureau's July 1 resident population estimates for 2025, largest first, with the change since 2020. Counties with fewer than 1,000 residents are not ranked. Areas without an estimate for the same year as the others are not ranked.
More rankings for New Mexico
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