Mary Leopoldina Burns (August 28, 1856 – June 3, 1942), was an American religious sister who was a member of the Sisters of St Francis of Syracuse, New York, and a close companion and biographer of Saint Marianne Cope during the 1883 Hansen's Disease epidemic on the island of Molokaʻi, Hawaii. Born on August 28, 1856, she was the daughter of James and Mary Burns, of Utica, New York. She joined the Sisters of St Francis of Syracuse, New York in 1881. After serving for nearly 40 years on Molokai, she retired in 1928 to the St. Francis Convent in Manoa Valley where she lived until her death.