Farmington is a city in San Juan County in the US state of New Mexico. As of the 2013 population estimate from the United States Census Bureau the city had a total population of 45,426 people. Farmington (and surrounding San Juan County) makes up one of the four Metropolitan Statistical Areas (MSA's) in New Mexico. The U.S. Census Bureau's population estimate in 2011 for Farmington was about 45,256.