Reiko Osawa was a Japanese diver. Osawa competed in the platform dive at the 1936 Berlin Olympics where she finished in fourth place. Osawa was the Japanese champion in high diving in 1935–36 and 1938. Her sister Masayo Osawa was also a diver at the 1936 Berlin Olympics. Both sisters travelled to the Berlin Olympics on the Trans-Siberian Railway with the Japanese delegation and returned home by boat via the Suez Canal. After World War II Osawa worked as a swimming instructor until she was 80 and was a high diving coach at Chuo University. Osawa also competed at the World Masters Swimming Championships. She died in 2010 at the age of 94.