Mayumi Aoki (青木まゆみ, born May 1, 1953) is a Japanese swimmer and Olympic champion. She competed at the 1972 Olympic Games in Munich, where she received a gold medal in 100 m butterfly. She received a bronze medal in the 100 m butterfly at the 1973 World Aquatics Championships in Belgrade.
Aoki improved the world record in 100 m butterly two times in 1972 (1:03.9 and 1:03.34).
She was inducted into the International Swimming Hall of Fame in Fort Lauderdale, Florida in 1989.