Nancy G. Siraisi (born 1932) is an American historian of medicine, and Distinguished Professor Emerita in History at Hunter College, and City University of New York. Nancy Siraisi received a B.A. (1953) and an M.A. (1958) from the University of Oxford and a Ph.D. (1970) from the City University of New York. She was a professor of history at Hunter College (1970–2003) and the Graduate Center (1976–2003) at the City University of New York.
Nancy Siraisi is a leading scholar in the history of medicine and science of the Middle Ages and the Renaissance. Her research has ranged widely across these two distinct fields, from her first book on the university curriculum in medieval Padua to her current work on the role of doctors in history-writing in the Renaissance.
Through her numerous publications and professional activities Nancy Siraisi has contributed to the growth of the history of science and medicine while also fostering the continued close interaction of these fields with "mainstream" history, notably through her faithful teaching of general medieval and Renaissance history and her insistence on careful contextualization.
- 2008 MacArthur Fellows Program 
- 2010 Charles Homer Haskins Prize Lecturer by the American Council of Learned Societies.
- Taddeo Alderotti and His Pupils: Two Generations of Italian Medical Learning, Books on Demand, 1981, ISBN 978-0-7837-9445-7
- The clock and the mirror: Girolamo Cardano and Renaissance medicine, Princeton University Press, 1997, ISBN 978-0-691-01189-9
- Medicine and the Italian universities, 1250-1600, BRILL, 2001, ISBN 9789004119420
- History, Medicine, and the Traditions of Renaissance Learning, University of Michigan Press, 2007, ISBN 978-0-472-11602-7
- Communities of Learned Experience: Epistolary Medicine in the Renaissance. Johns Hopkins University Press, 2013, ISBN 978-1421407494
- Natural particulars: nature and the disciplines in Renaissance Europe, Editors Anthony Grafton, Nancy G. Siraisi, MIT Press, 1999, ISBN 978-0-262-07193-2
- Historia: empiricism and erudition in early modern Europe, Editors Gianna Pomata, Nancy G. Siraisi, MIT Press, 2005, ISBN 978-0-262-16229-6