Henry Melvin Hart Jr. (1904–1969) was an American legal scholar who was an influential member of the Harvard Law School faculty from 1932 until his death.
Born in Butte, Montana, Hart received his A.B. from Harvard College in 1926 and attended Harvard Law School, where he was president of the Harvard Law Review and received an LL.M. in 1930 and an S.J.D. in 1931. Following work for then-Professor Felix Frankfurter, Hart clerked for Supreme Court Justice Louis Brandeis and then returned to Harvard Law School, where he was a fixture until his death at 64. An "ardent supporter of the New Deal" and of President Franklin D. Roosevelt,World War II and the Cold War led Hart to evolve "from a dedicated progressive into a theorist of social stability, cultural consensus, and institutional balance." That evolution led Hart to seek institutional solutions to protect the rule of law from overreaching by Congress and the executive. That approach became the inspiration for the new "Legal Process" school of American jurisprudence.
The legal process school was first given definition by Hart's manuscript of the same name, co-authored with Albert M. Sacks. Originally planned for publication by Foundation Press in 1956, the manuscript was organized into seven chapters, with 55 "problems" which guided the student through Hart and Sacks proposed approach to important American law cases. Despite being widely circulated in manuscript form, which itself went through four major editions, the Legal Process was not published in book form by Foundation Press until 1994. The manuscript editions, however, were widely circulated and very influential among the professoriate, many of whom used it as the foundation for courses at Harvard Law and other institutions.