Copalillo is a city and seat of the municipality of Copalillo, in the state of Guerrero, south-western Mexico. ...[municipality] Copalillo is one of the 81 municipalities of Guerrero, in south-western Mexico. The municipal seat lies at Copalillo. The municipality covers an area of 898.6 km². As of 2005, the municipality had a total population of 13,747. ...