Jonathan Simon Christopher Riley-Smith, K.St.J., Ph.D. MA, Litt.D., FRHistS (born 27 June 1938) is an historian of the Crusades, and a former Dixie Professor of Ecclesiastical History. He is a Fellow of Emmanuel College, Cambridge.
He was educated at Eton College and Trinity College, Cambridge, where he took his BA (1960), MA (1964), PhD (1964), and LittD (2001).
During his career, he has taught at the University of St Andrews, Queens' College, Cambridge, Royal Holloway College, London as well as at Trinity College.
He was a founder of the Society for the Study of the Crusades and the Latin East. He is also a Knight of Grace and Devotion, Sovereign Military Order of Malta and a Knight of Justice, Most Venerable Order of the Hospital of Saint John of Jerusalem.
He is married with three children.
- The Knights of St John in Jerusalem and Cyprus, c.1050-1310 (London, Macmillan, 1967 repr. 2002)
- Ayyubids, Mamlukes and Crusaders. Selections from the Tarikh al-Duwal wa'l Muluk of Ibn al-Furat (with Ursula and Malcolm C. Lyons), 2 vols. (Cambridge, Heffer, 1971)
- The Feudal Nobility and the Kingdom of Jerusalem, 1174-1277 (London, Macmillan, 1973 repr 2002)
- What Were the Crusades? (London, Macmillan, 1977 2nd edition 1992 3rd edition Basingstoke, Palgrave, 2002)
- The Crusades: Idea and Reality, 1095-1274 (with Louise Riley-Smith) (London, Edward Arnold, 1981)
- The First Crusade and the Idea of Crusading (London and Philadelphia, Athlone/ University of Pennsylvania Press, 1986, paperback US 1990, UK 1993)
- The Crusades: A Short History -London and New Haven, Athlone/ Yale University Press, 1987, also in paperback) � (translated into French, Italian and Polish)
- The Atlas of the Crusades (editor) (London and New York, Times Books/ Facts on File, 1991) - (translated into German and French)
- The Oxford Illustrated History of the Crusades (editor) (Oxford,Oxford University Press, 1995, paperback 1997) � (now reissued as The Oxford History of the Crusades, paperback, 1999) - (translated into Russian, German and Polish)
- Cyprus and the Crusades (editor, with Nicholas Coureas) (Nicosia, Society for the Study of the Crusades and the Latin East and Cyprus Research Centre, 1995)
- Montjoie: Studies in Crusade History in Honour of Hans Eberhard Mayer (editor, with Benjamin Z. Kedar and Rudolf Hiestand) (Aldershot, Variorum, 1997)
- The First Crusaders, 1095-1131 (Cambridge, Cambridge University Press, 1997, paperback 1998, 2000)
- Hospitallers: The History of the Order of St. John (London, The Hambledon Press, 1999, also in paperback)
- Al seguito delle Crociate Rome (Di Renzo: Dialoghi � Uomo e Societΰ), 2000
- Dei gesta per Francos: Etudes sur les croisades dιdiιes ΰ Jean Richard (editor, with M.Balard and B.Z.Kedar) Aldershot (Ashgate), 2001
- The Crusades, Christianity, and Islam (Columbia University Press, 2008)