Harry Kalven, Jr. (September 11, 1914 – October 29, 1974) was an American jurist, regarded as one of the preeminent legal scholars of the 20th century. He was the Harry A. Bigelow Professor of Law at the University of Chicago Law School. Kalven coauthored, with Charles O. Gregory (and later Richard Epstein), the most widely used textbook in the field of torts, "Cases and Materials on Torts." Kalven was also a leading scholar in the field of constitutional law, particularly in the area of the first amendment. Kalven is the author of a number of seminal books and articles. Kalven is the coauthor of "The Contemporary Function of the Class Suit," one of the most heavily cited articles in the history of American law, and widely considered to be the foundation of the modern class action lawsuit. He also co-authored a pioneering empirical study of The American Jury with his Chicago colleague Hans Hans Zeisel.