The state of New Mexico is divided into 32 counties. Bernalillo County is the oldest (formed in 1852) while Cibola County is the youngest (established in 1981).

Bernalillo County is the most populous, with a population of 670,968 people. Catron County has the most land area (17,943 km2), while Los Alamos County has the smallest (282 km2).

Please find a list of all New Mexico counties listed alphabetically below.

• Bernalillo County, NM
• Catron County, NM
• Chaves County, NM
• Cibola County, NM
• Colfax County, NM
• Curry County, NM
• De Baca County, NM
• Eddy County, NM
• Grant County, NM
• Guadalupe County, NM
• Harding County, NM
• Hidaigo County, NM
• Lea County, NM
• Lincoln County, NM
• Los Alamos County, NM
• Luna County, NM
• McKinley County, NM
• Mora County, NM
• Otero County, NM
• Quay County, NM
• Rio Arriba County, NM
• Roosevelt County, NM
• San Juan County, NM
• San Miguel County, NM
• Sandoval County, NM
• Santa Fe County, NM
• Sierra County, NM
• Socorro County, NM
• Taos County, NM
• Torrance County, NM
• Union County, NM
• Valencia County, NM