Santa Rosa is a city in and the county seat of Guadalupe County, New Mexico, United States. The population was 2,848 at the 2010 census. It lies between Albuquerque and Tucumcari, situated on the Pecos River at the intersection of Interstate 40, U.S. Route 54, and U.S. Route 84. The city is located west of, but not within, the Llano Estacado or "staked plains" of eastern New Mexico and west Texas.