Mary Aileen Conquest-Allen (December 22, 1888 – September 4, 1950) was an American diver who competed in the 1920 Summer Olympics. She was born on Prince Edward Island, Canada. In 1913, Allen was one of the founding members of an all-woman swimming club at the Bimini Baths in Los Angeles, California, which was formed in response to strict dress codes imposed by other clubs. She was later elected captain of the club. In 1920, she finished fourth in the 3 metre springboard event.