John Ordronaux (1830 - January 20, 1908) was an American Civil War army surgeon, a professor of medical jurisprudence, a pioneering mental health commissioner and a generous patron of university endowments. Between 1859 and 1901 Ordronaux published at least fifteen books and articles about subjects as diverse as heroes of the American Revolution of 1776, military medicine, medical jurisprudence, mental health, United States constitutional law and historical treatises. He left an estate worth $2,757,000 much of which he gave in endowments to several US universities and other institutions. He did not marry.