The American Aborigines are a hypothetical group of people, originally from Oceania, who crossed the Pacific Ocean and arrived in South America long before the ancestors of today's American Indian peoples came there. The American Aborigines are claimed to have overspread much of South America before being nearly exterminated by the invaders coming from the north.

The first hint of an American Aborigine settlement of South America came from cave paintings in Brazil. The paintings, which predated the supposed date of settlement of the area, depict rituals never before seen in native American art. Somewhat later paintings from the same area depict war and violence, and then the paintings cease.

The rites shown in the paintings, involving elaborate costumes, are still performed by Australian Aborigines today. Similar rites existed in the traditions of the natives of Tierra del Fuego until the Fuegians ceased to exist as a people in the 20th century. The Fuegians are believed to be the product of intermarriage between American Aborigines and American Indians - the last surviving descendants of the Aboriginal settlers. Physiological evidence of Aborigines has also been found.