Morris Leo Cohen (November 2, 1927 – December 18, 2010) was an American attorney who left the practice of law to become a law librarian and professor of law at the University at Buffalo, University of Pennsylvania, Harvard Law School and Yale Law School. Described by The New York Times as "one of the nation's most influential legal librarians", he wrote extensively about the history of law and helped organize and computerize the law libraries at Harvard and Yale. A resident of New Haven, Connecticut, Cohen died at the age of 83 of leukemia on December 18, 2010, at his home there.