Mary Cain may refer to:
Mary Cain (editor) (1904–1984), American newspaper editor and political activist Mary Cain (athlete) (born 1996), American middle-distance runner Mary Jane Cain (1844–1929), Australian Aboriginal leader
See also Mary Kane (born 1962), American attorney and politician Lucy Cane (c. 1866–1926), Irish public servant, also known as Mary Cane