Mayumi Aoki (青木 まゆみ, Aoki Mayumi; born May 1, 1953) is a Japanese swimmer. She competed at the 1972 Summer Olympics in the 100 m and 200 m butterfly and 4 × 100 m medley relay and won a gold medal in the 100 m butterfly. She won a bronze medal in this event at the 1973 World Aquatics Championships. In 1972 she twice broke the world record in the 100 m butterfly. After retiring from competition she worked as a swimming coach and a high school teacher. In 1989 she was inducted into the International Swimming Hall of Fame.