*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
