Santa Fe County is located in the U.S. state of New Mexico. As of the 2020 census, the population was 154,823, making it New Mexico's third-most populous county, after Bernalillo County and Doña Ana County. Its county seat is Santa Fe, the state capital. Santa Fe County includes the Santa Fe metropolitan statistical area, which is also included in the Albuquerque–Santa Fe–Las Vegas combined statistical area.