Aconchi is a small city in Aconchi Municipality that surrounds it, located in the center of the Mexican state of Sonora. The population of the municipality was 2,452 in 2005 in an area of 358.74 square kilometers. It became a municipality in 1932. The mission San Pedro Aconchi was founded in 1639 by the Jesuit missionaries Bartolomé Castaños and Pedro Pantoja. The municipal seat lies at an elevation of 609 meters above sea level.