Cerro Overo is a volcanic crater in Chile. It lies at the foot of Chiliques volcano and close to Laguna Lejía, over ignimbrites of Pliocene age erupted by the La Pacana volcano. It is 480 by 580 metres wide and 72 metres (236 ft) deep and formed through combined explosive-effusive eruptions. The lavas are of lower crustal provenience and are among the least silicic in the region.