David Samuel Margoliouth (17 October 1858, London – 22 March 1940, London) was an orientalist. He was briefly active as a priest in the Church of England. He was Laudian Professor of Arabic at the University of Oxford from 1889 to 1937.
His father, Ezekiel, had converted from Judaism to Anglicanism, and thereafter worked in Bethnal Green as a missionary to the Jews; he was also close to his uncle, the Anglican convert Moses Margoliouth. Margoliouth was educated at Winchester, where he was a scholar, and at New College, Oxford where he graduated with a double first in Greats and won an unprecedented number of prizes in Classics and Oriental languages, of which he had mastered Arabic, Persian, Turkish, Armenian and Syriac, in addition to Hebrew. His academic disseration, published in 1888, was entitled Analecta Orientalia ad Poeticam Aristoteleam. In 1889 he succeeded to the Laudian Chair in Arabic, a position he held until he retired, from ill health, in 1937. He received the degree Doctor of Letters (D. Litt.) from the New College, Oxford, in July 1902.
Many of his works on the history of Islam became the standard treatises in English, including Mohammed and the Rise of Islam (1905), The Early Development of Mohammedanism (1914), and The Relations Between Arabs and Israelites Prior to the Rise of Islam (1924).
He was described as a brilliant editor and translator of Arabic works, as seen in The Letters of Abu'l-'Ala of Ma'arrat al-Nu'man (1898), Yaqut's Dictionary of Learned Men, 6 vol. (1907–27), and the chronicle of Miskawayh, prepared in collaboration with H. F. Amedroz under the title The Eclipse of the 'Abbasid Caliphate, 7 vol. (1920–21). Some of David Samuel Margoliouth's studies are included in The Origins of The Koran: Classic Essays on Islam’s Holy Book edited by Ibn Warraq.