Buell Halvor Quain (May 31, 1912 – August 2, 1939) was an American ethnologist who, after graduating from University of Wisconsin–Madison and studying as a graduate student at Columbia University, worked with native peoples in Fiji and Brazil. He published a total of four books, three of them posthumously. In 1938, Quain travelled to Brazil to work with the Kraho people of the Brazilian rainforest, where he also spent time in the Trumai village.