Valencia County (Spanish: Condado de Valencia) is a county in the U.S. state of New Mexico. As of the 2020 census, the population was 76,205. The county seat is Los Lunas.

Valencia County is included in the Albuquerque Metropolitan Statistical Area.

The county was a significant bellwether region that held the longest record for predicting presidential election winners until 2020.

The county, which had been previously larger in area, lost almost 81 percent of its territory on June 19, 1981, upon the creation of Cibola County, which occupies the westernmost portion of Valencia County's former area.

According to the U.S. Census Bureau, the county has a total area of 1,068 square miles (2,770 km²), of which 1,066 square miles (2,760 km²) is land and 2.1 square miles (5.4 km²) (0.2%) is water. It is the second-smallest county in New Mexico by area.

As of the 2020 census, the county had a population of 76,205. The median age was 39.8 years, 23.7% of residents were under the age of 18, and 18.3% of residents were 65 years of age or older. For every 100 females there were 101.8 males, and for every 100 females age 18 and over there were 100.4 males age 18 and over.

The racial makeup of the county was 51.8% White, 1.3% Black or African American, 4.3% American Indian and Alaska Native, 0.6% Asian, 0.1% Native Hawaiian and Pacific Islander, 18.7% from some other race, and 23.4% from two or more races. Hispanic or Latino residents of any race comprised 60.1% of the population.

70.0% of residents lived in urban areas, while 30.0% lived in rural areas.