Apatzingán (in full, Apatzingán e la Constitución) is a city and its surrounding municipality located in the west-central part of the state of Michoacán, Mexico. The city is the fourth-largest in Michoacán (behind Morelia, Uruapan, and Zamora), with a 2005 census population of 93,180 persons. The municipality of Apatzingán has an area of 1,656.67 km² (639.64 sq mi) and reported a population of 115,078.