Raoul Weston La Barre (1911-1996) was an American anthropologist, best known for his work in ethnobotany, particularly with regard to Native-American religion, and for his application of psychiatric and psychoanalytic theories to ethnography.

In a 1961 article, La Barre wrote that "It was [La Barre's teacher at Yale] Edward Sapir, more than any other person, who first effectively imported psychoanalysis into the body of American anthropology...At a time when the official anthropological journals were systematically ignoring psychoanalysis and the prevailing climate of opinion was chilly if not hostile, Sapir was giving his students as required reading the works of Abraham, Jones, Ferenczi and other classic writers."

In 1937 La Barre was made a Sterling Fellow at Yale, and conducted field work in South America with the Aymara of Lake Titicaca region and the Uros of the Rio Desaguadero.

He published The Aymara Indians of the Lake Titicaca Plateau and They Shall Take up Serpents: Psychology of the Southern Snake-handling Cult, which are regarded as landmark studies of indigenous peoples in the Amazon and the extremist culture of Christian fundamentalism lurking in the urban and rural landscapes of contemporary America.

During the 1950s and 1960s, La Barre became absorbed in the study of altered states of consciousness precipitated by the ingestion of shamanistic plants from peyote and ayahuasca to magic mushrooms.

Collaborating with Schultes and R. Gordon Wasson, La Barre conducted profoundly original investigations into the anthropology and archeology of altered states of consciousness.