Mary Allen or Allan may also refer to:
Mary Wood-Allen (1841–1908), American doctor, social reformer, lecturer, and writer
Mary Electa Allen (1858–1941), American photographer
Mary Allan (British academic) (1869–1956), British academic, principal of Homerton College, Cambridge
Mary Hayes Allen (1875–1935), American educator
Mary Sophia Allen (1878–1964), Welsh-born suffragette who was an early police woman and a far right leader
Aileen Allen (Mary Aileen Allen, 1888–1950), American diver who competed in the 1920 Summer Olympics
Mary Cecil Allen (1893–1962), Australian artist, writer and lecturer
Mary Parsons Reid Allan (1917–2002), Scottish artist
Mary Belle Allen (1922–1973), American botanist and chemist
Mary Love (Mary Ann Allen, 1943–2013), American singer
Mary Allen (arts administrator) (born 1951), British writer, broadcaster, arts administrator and management consultant
Elyse Allan (Mary Elyse Allan, born 1956/7), Canadian businesswoman
Mary Cecelia Allen, American writer and writing coach
Mary Allen (politician), American politician from New Hampshire