Gondwanatherium is a genus of mammal from the extinct suborder Gondwanatheria that lived in Patagonia, South America during the "Age of Dinosaurs", specifically the Upper Cretaceous.

The genus and species were named by the Argentinian paleontologist José Bonaparte in 1986 (Bonaparte, 1986). Gondwanatherium means Gondwana beast.

The position of gondwanatherians within class Mammalia is not yet clear.