Masayo Ōsawa (Japanese: 大沢 政代, Hepburn: Ōsawa Masayo, April 28, 1913 – January 1946) was a Japanese diver. She competed at the 1936 Summer Olympics and finished sixth in the 3 m springboard and 14th in the 10 m platform competition. During World War II Ōsawa served in the Japanese Army as a nurse and died of an illness six months after the end of military operations in Northern China.