Thomas Fredrik Weybye Barth (born 22 December 1928 in Leipzig) is a Norwegian social anthropologist who has published several ethnographic books with a clear formalistic view. He is professor in the Department of Anthropology at Boston University, and has previously held professorships at the University of Oslo, the University of Bergen (where he founded the Department of Social Anthropology), Emory University and Harvard University.

In Balinese Worlds, Fredrik Barth proposes a new model for anthropological analysis of complex civilizations that is based on a fresh, synthetic account of culture and society in North Bali and one that takes full notice of individual creativity in shaping the contours of this dynamic culture.

In this detailed ethnography of the Northern district of Buleleng, Barth rejects mainstream anthropological generalizations of Bali as a cultural system of carefully articulated parts. Instead—drawing on many sources, including the sociology of knowledge, interactional analysis, postmodern thought, and his own exceptionally varied field experience—Barth presents a new model that actually generates variation. Barth's innovative analysis of Balinese life highlights both the constructive and the disorganizing effects of individual action, the constant flux of interpretation, and the powerful interaction of memory and social relationships, and knowledge as a cultural resource.

Balinese Worlds is a unique contribution not only to Balinese studies but also to the theory and methods of the anthropology of complex societies.