Gerard E. Lynch was appointed to the United States Court of Appeals for the Second Circuit by President Obama in 2009. From 2000 through 2009 he served on the United States District Court for the Southern District of New York, to which he was appointed by President Clinton. Before his appointment, Judge Lynch was both an academic and a practitioner, teaching at the Columbia University School of Law and practicing criminal law as both a prosecutor and defense lawyer. He continues to be Paul J. Kellner Professor of Law at Columbia University School of Law. In 2009, he received the Edward Weinfeld Award for Distinguished Contributions to the Administration of Justice from the New York County Lawyers' Association, and in 2016, the Learned Hand Medal for Excellence in Federal Jurisprudence from the Federal Bar Council. Columbia awarded him its annual Wien Prize for Social Responsibility in 2008, and its Medal for Excellence in 2018.

A life-long New Yorker, Judge Lynch was educated at Regis High School, Columbia College, and the Columbia University School of Law, in each case graduating first in his class. Following law school, he clerked for Judge Wilfred Feinberg of the United States Court of Appeals for the Second Circuit, and for Justice William J. Brennan, Jr., of the United States Supreme Court.

After clerking, he joined the faculty of the Columbia University School of Law in 1977, where he has taught ever since, rising through the academic ranks to an appointment as full Professor in 1986 and being named Paul J. Kellner Professor of Law in 1996. From 1992-1997 he served as Vice Dean of the Law School, with supervisory responsibility for curriculum, adjunct faculty and student services. In 1994, he received the student-voted Willis Reese Award for Excellence in Teaching, and in 1997, he was the first member of the Faculty of Law to receive the university-wide President's Award for Outstanding Teaching. He has taught as a visiting professor or lecturer at the Hebrew University in Jerusalem, Tokyo University, and the Universities of Leiden, Amsterdam and Buenos Aires. Judge Lynch is the author of various academic and popular articles about criminal law and procedure, constitutional law, and legal ethics, most notably a book-length study of criminal RICO, an influential account of our de facto administrative process of criminal adjudication and a number of articles about sentencing.

As a practitioner, Judge Lynch took leaves from Columbia to serve full-time as an Assistant United States Attorney for the Southern District of New York from 1980 to 1983, where he prosecuted white-collar criminal cases and served as Chief Appellate Attorney, and again from 1990 to 1992, when he served as Chief of the Criminal Division in that office. On a part-time or consulting basis he has been appointed counsel to city, state, and federal commissions and special prosecutors investigating public corruption, including the Iran/Contra investigation, where among other responsibilities he briefed and argued the prosecution position in the appeal of Oliver North.

In addition to his government service, Judge Lynch has briefed and argued cases in federal appellate courts, including the Supreme Court, as a cooperating attorney with the American and New York Civil Liberties Unions, and has extensive experience as a defense attorney, particularly in federal cases. From 1992 to 2000 he was counsel to the New York firm of Howard, Darby & Levin (and its successor firms, Howard, Smith & Levin and Covington & Burling).

Judge Lynch is a member of the Council of the American Law Institute, and has served on numerous committees of the Association of the Bar of the City of New York, the New York State Bar Association, and the New York Council of Defense Lawyers.