The Peru-Chile Trench, also called Atacama Trench, is a submarine trench in the eastern Pacific Ocean, about 100 miles (160 km) off the coast of Peru and Chile. It reaches a maximum depth of 26,460 feet (8,065 m) below sea level in Richards Deep and is approximately 3,666 miles (5,900 km) long; its mean width is 40 miles (64 km) and it covers an expanse of some 228,000 square miles (590,000 square km).

The trench is a result of the eastern edge of the Nazca Plate being subducted under the South American Plate.

The Peru-Chile Trench, the forearc and the western edge of the central Andean plateau (Altiplano) delineate the dramatic "Bolivian Orocline" that defines the Andean slope of southern Peru, northern Chile, and Bolivia.