Before moving to Yale in 1989, Langbein was the Max Pam Professor of American and Foreign Law at the University of Chicago. In the 1997-98 academic year he served as the Goodhart Professor of Legal Science at Cambridge University. From 1990 to 2001 he was Chancellor Kent Professor of Law and Legal History at Yale. He has also held academic appointments at Stanford University, Oxford University, and the Max Planck Institutes in Frankfurt and Freiberg, Germany. He is an honorary fellow of Trinity Hall, Cambridge.
Law reform work. Langbein has served continuously as a Uniform Law Commissioner under gubernatorial appointments from Illinois and Connecticut since 1984. He was the reporter and principal drafter for the Uniform Prudent Investor Act (1994), which governs fiduciary investing in most American states. He has served on drafting committees for numerous acts in the fiduciary fields, including the Uniform Probate Code (1989-90 revisions), the Uniform Principal & Income Act (1997), the Uniform Trust Code (2000), and the Uniform Prudent Management of Institutional Funds Act (2006). For the American Law Institute, Langbein served as associate reporter for the Restatement of Property (Third): Wills and Donative Transfers (3 vols. 1999-2011); and as an advisor for the Restatement (Third) of Trusts (1987-2012).
Investment, trust, pension, and probate law. Langbein has written extensively in the leading law reviews about investment, trust, pension, and probate law. The movements to unify the constructional law of probate and nonprobate transfers, and to excuse harmless errors in the execution and content of wills, now codified in the Uniform Probate Code and in the Restatement (Third) of Property, trace to his scholarship: 18 Probate & Property (Jan. 2004); 87 Columbia L. Rev. 1 (1987); 97 Harvard L. Rev. 1108 (1984); 130 U. Pa. L. Rev. 521 (1982) (with Waggoner); 88 Harvard L. Rev. 489 (1975).
Langbein’s work on trust law has emphasized the influence of modern portfolio theory on fiduciary investing, the contractual dimensions of trusteeship, the growing use of commercial trusts, the extent and purpose of mandatory rules, and the changing character of the duty of loyalty: 114 Yale L.J. 929 (2005); 98 Northwestern U.L. Rev. 1109 (2004); 107 Yale L.J. 165 (1997); 81 Iowa L. Rev. 641 (1996); 105 Yale L.J. 625 (1995; 62 A.B.A.J. 887 (1976) (with Posner).
Following enactment of ERISA (1974), Langbein had a shaping role on the development of pension and employee benefit law as a scholarly field. He co-authors the principal coursebook used in American law schools: Langbein, Pratt, Stabile & Stumpff, Pension and Employee Benefit Law (Foundation Press, 6th ed. 2015). His scholarly work has focused on ERISA fiduciary and remedy law: 101 Northwestern U.L. Rev. (2007); 103 Columbia L. Rev. 1317 (2003);  Supreme Court Rev. 207; 55 U. Chicago L. Rev. 1105 (1988)(with Fischel).
Langbein has served as a consultant and expert witness in pension and trust litigation, and he has appeared in a series of training videos for bank trust officers on aspects of trust and fiduciary practice. He has also testified in Congressional hearings on issues of policy facing the private pension system.
Legal history; civil and criminal justice. Langbein has written a series of articles and books on the history of Anglo-American criminal procedure, as well as books and articles contrasting modern Anglo-American civil and criminal procedure with Continental practice. In 2009 he published a textbook, History of the Common Law: The Development of Anglo-American Legal Institutions with R. Lerner & B. Smith (Aspen 2009). Langbein's book, The Origins of Adversary Criminal Trial (Oxford U.P. 2003), which traces the history of the Anglo-American adversary system of criminal justice, received the Coif Biennial Book Award (2006) as the outstanding American book on law for the period 2003-04. His book on the history of the law of torture, first published in 1977, was republished with a new preface in 2006: Torture and the Law of Proof: Europe and England in the Ancient Regime (Chicago U.P. 2006). In 2000 the American Society for Legal History awarded him the Sutherland Prize for his "pioneering work." His historical account of the disappearance of civil trial in the United States appears in 122 Yale L.J. 522 (2012).
Comparative law. Langbein’s work on comparative law has advanced the position that European-style nonadversarial justice is fairer, more accurate, and more economical than Anglo-American procedures: 15 Harvard J.L. & Pub. Pol. 119 (1992); 52 U. Chicago L. Rev. 823 (1985); 78 Michigan L. Rev. 204 (1979).
Memberships. Langbein's memberships include the American Academy of Arts and Sciences, the British Academy, the International Academy of Comparative Law, the International Association of Procedure Law, the American College of Trust and Estate Counsel, and the International Academy of Estate and Trust Law. He is admitted to the bar in Florida and the District of Columbia, and as a barrister of the Inner Temple in England.
Education. After completing an undergraduate degree in economics at Columbia University in 1964, Langbein studied law and legal history for seven years in England, Germany, and the United States. He graduated magna cum laude from the Harvard Law School, where he was an articles editor of the Harvard Law Review. He received his degree in English law with first class honours from Cambridge University (Trinity Hall). He earned his Ph.D. from Cambridge in 1971. His Ph.D. thesis won the Yorke Prize (1973); published as Prosecuting Crime in the Renaissance: England, Germany, France (Harvard U.P. 1974), the book has been recurrently cited in opinions of the U.S. Supreme Court.