Fenlon was born to Albert Fenlon and Joan Fenlon (née Rainey).
He has contributed articles to several music publications and is the author of the books Music and Culture in Late Renaissance Italy (Oxford University Press, 2000), The Ceremonial City: History, Memory and Myth in Renaissance Venice (Yale University Press, 2007). and Piazza San Marco (Harvard University Press, 2009). His writings often explore the relationship between the evolution and development of music and changes within society.
He is currently a fellow and Emeritus Professor of Historical Musicology at King's College of the University of Cambridge, England and serves as the editor of the journal Early Music History. Fenlon is also Honorary Keeper of the Music at the Fitzwilliam Museum.
- "FENLON, Prof. Iain Alexander". Who's Who 2014. A & C Black. December 2013. Retrieved 26 October 2014.
- "Renaissance music scholar to deliver Pope Lecture April 15". University of North Carolina website.
- Rosemary Williamson. "Fenlon, Iain." In Grove Music Online. Oxford Music Online, http://www.oxfordmusiconline.com/subscriber/article/grove/music/47085 (accessed February 19, 2012)