Mary Bateson (12 September 1865, Robin Hood's Bay – 30 November 1906) was a British historian and suffrage activist.
Bateson was the daughter of William Henry Bateson, Master of St John's College, Cambridge, and Anna Aikin. The geneticist William Bateson was her older brother, Margaret Heitland was her sister. She was educated at the Perse School for Girls and Newnham College, Cambridge. She spent her entire professional life at Newnham, teaching there from 1888 and becoming a Fellow in 1903. Known for her writings in medieval history, she was supported professionally by historians Mandell Creighton and F. W. Maitland.