Cerro del Azufre (Spanish pronunciation: [ˈsero ðel aˈsufɾe]) is a stratovolcano located in El Loa Province, Antofagasta Region, Chile.

Cerro del Azufre lies in northern Chile, close to the border with Bolivia and south of the Salar de Ascotan.

The northern edifice bears evidence of a sector collapse that produced a northward debris avalanche,[11] which was later buried by lava flows.

[17] During the last 10 million years, caldera eruptions in the Altiplano-Puna volcanic complex (APVC) have generated ignimbrites and lavas which underlie Cerro del Azufre.

[17] Volcanic rocks from Cerro del Azufre define an andesite to dacite suite, with plagioclase phenocrysts.

The first stage crops out at isolated sites on the southern flank, and consists of eroded lava flows; one age of 1.1±0.2 million years may be attributable to this unit.

[10] Seismic tomography[29] and electrical conductivity analysis has identified a zone under the volcano that may be either a magma chamber or a hydrothermal system.

The field reaches the surface in the Apacheta-Aguilucho volcanic complex but may extend over an area of 25 square kilometres (9.7 sq mi) underground.