Jonathan James Graham Alexander (born 1935), known in print as J. J. G. Alexander, is a medievalist and expert on manuscripts, "one of the most profound and wide-ranging of all historians of illuminated manuscripts".
Alexander edited the Survey of Manuscripts Illuminated in the British Isles from 1975 onwards. In 1988 he became Sherman Fairchild Professor of Fine Arts at the New York University Institute of Fine Arts.
(ed. with Otto Pächt) Illuminated manuscripts in the Bodleian Library, Oxford, 1966Italian Renaissance illuminations, New York: Braziller, 1977Insular manuscripts, 6th to the 9th century, London: H. Miller, 1978. Survey of manuscripts illuminated in the British Isles vol. 1.The decorated letter, New York: Braziller, 1978(ed. with T. Julian Brown and Joan Gibbs) Collected writings of Francis Wormald. 2 vols, New York: Oxford University Press, 1984-88.(ed. with Paul Binski) Age of chivalry : art in Plantagenet England, 1200-1400, London: Royal Academy of Arts, 1987Medieval illuminators and their methods of work, New Haven: Yale University Press, 1994(ed.) The Painted page : Italian Renaissance book illumination, 1450-1550, New York: Prestel, 1994(ed. with James H. Marrow and Lucy Freeman Sandler) The splendor of the word: medieval and Renaissance illuminated manuscripts at the New York Public Library, New York: New York Public Library, 2005. 