Robert Fritz Graebner (4 March 1877, Berlin – 13 July 1934, Berlin) was a German geographer and ethnologist best known for his development of the theory of Kulturkreis, or culture circle. He was the first theoretician of the Vienna School of Ethnology. Graebner advanced a theory of diffusion of culture (Kulturkreise) which became the basis of a culture-historical approach to ethnology. His theories had influence for a time in the field of ethnology, and were also propounded by Franz Boas, Clark Wissler and Paul Kirchhoff. He also induced the concept of "primeval culture".