Mission is a city in Hidalgo County, Texas, United States. The population was 77,058 at the 2010 census Mission is one of the principal cities of the McAllenEdinburgMission metropolitan area. According to the United States Census Bureau, the city has a total area of 24.1square miles (62Square kilometers), of which, 24.1square miles (62Square kilometers) of it is land and 0.04% is water. As of the census of 2000, there were 45,408people, 13,766households, and 11,384families residing in the city. The population density was 1,881.9people per square mile (726.6Square kilometers). There were 17,723housing units at an average density of 734.5per square mile (283.6Square kilometers).