Reo Franklin Fortune (1903–1979) was a New Zealand social anthropologist. Originally trained as a psychologist, Fortune was a lecturer in social anthropology at the Cambridge University, and a specialist in Melanesian language and culture.[1] He was married to Margaret Mead, with whom he undertook field studies in New Guinea, from 1928 to 1935.[2] He is also known for his contribution to mathematics with his study of Fortunate numbers in number theory.[3]