Find out about the list of all New Mexico counties in alphabetical order, including their size, seats and numbers. The U.S. state of New Mexico has 33 counties. Here is the full list in alphabetical order: B Bernalillo County (NM) C Catron County (NM) Chaves County (NM) Cibola County (NM) Colfax County (NM) Curry County (NM) D De Baca County (NM) Doña Ana County (NM) E Eddy County (NM) G Grant County (NM) Guadalupe County (NM) H Harding County (NM) Hidalgo County (NM) L Lea County (NM) Lincoln County (NM) Los Alamos County (NM) Luna County (NM) M McKinley County (NM) Mora County (NM) O Otero County (NM) Q Quay County (NM) R Rio Arriba County (NM) Roosevelt County (NM) S Sandoval County (NM) San Juan County (NM) San Miguel County (NM) Santa Fe County (NM) Sierra County (NM) Socorro County (NM) T Taos County (NM) Torrance County (NM) U Union County (NM) V Valencia County (NM) New Me...