Mary Dorothy Rose Leys (8 October 1890 – 6 September 1967) was a British historian and academic, who was involved in the work of the Catholic Social Guild and the Catholic Record Society. Leys was born in Tylers Green, Buckinghamshire. Her obituary in The Times states that she was educated at home because her family were too poor to afford school fees. Her Scottish father, John Kirkwood Leys, was a novelist and died in 1909. In 1911, she was awarded a scholarship to Somerville College, Oxford. She taught History at St Anne's College, Oxford from 1919 until her retirement in 1955.