Defensores del Chaco National Park, National park in northern Paraguay.

Defensores del Chaco National Park covers 720,723 hectares in the departments of Alto Paraguay and Boquerón, making it Paraguay's largest national park. The terrain is a flat Chaco plain of dry xerophytic vegetation, with white quebracho, palo santo, coronillo and several algarrobo species, plus cacti and clavel del aire. The Cerro León massif, about 40 km across and reaching 600 m above sea level, rises from this plain.

Paraguay created the park on 6 August 1975 by Executive Decree No. 16,806, with an original area of 7,800 km², now about 7,197 km². It is the country's largest national park, spanning Alto Paraguay and Boquerón departments. Its mandate is to keep viable populations of endangered species and the ecological processes of the tropical dry forest.

The park's forests are home to the Ayoreo, a people living there without contact with outsiders, as documented in the sources. Visitors should not expect to meet them: the park is entered only with a guide, and in May 2018 an Austrian tourist disappeared and was not found after a 25-day search.

Four-wheel drive vehicles are needed to navigate the unpaved roads throughout the protected area. Simple camping facilities are available for those planning overnight stays within the park.

Cerro León is a mountain massif about 40 km across that rises from the Chaco plain to 624 m above sea level. It is the park's highest point and the main landmark in an otherwise flat landscape.