Judge John Gleeson is a trial and appellate lawyer and company advisor who, before joining the firm in 2016, was a federal judge for 22 years and, prior to that, a federal prosecutor for ten years. He is a litigation partner in the White Collar & Regulatory Defense and Commercial Litigation Groups. A fellow of the American College of Trial Lawyers, Judge Gleeson’s practice focuses on white collar defense, complex civil litigation, internal investigations, and dispute resolution. Since joining Debevoise, Judge Gleeson has been lead trial counsel in lengthy civil and criminal trials and in various evidentiary hearings in both federal and state courts, and has argued more than a dozen appeals.

On the white-collar side, Judge Gleeson is ranked in Band 1 by Chambers USA (2023) for White-Collar and Government Investigations, where clients have described him as “a skillful trial lawyer with great judgment” who “commands authority and respect.” He was named to Forbes’ 2024 America’s Top 200 Lawyers list and is a 2023 inductee into Lawdragon’s Hall of Fame, which recognizes “outstanding lawyers who have made remarkable contributions to the legal profession.” He tries criminal cases, argues criminal appeals, and is recognized as one of the nation’s foremost experts in federal criminal law. Indeed, on three occasions Judge Gleeson has been appointed by federal judges as amicus curiae to argue important issues of federal criminal law and procedure, including to make the successful argument against the Trump administration’s motion to dismiss the prosecution of former National Security Advisor Michael Flynn.

With respect to sentencing, Judge Gleeson, known as a reformer and scholar while on the bench, was appointed in 2022 by President Biden and confirmed by the United States Senate to the United States Sentencing Commission, where he serves as a Commissioner.

As for commercial litigation, capitalizing on his 22 years of experience presiding over complex civil cases, Judge Gleeson is both an active trial and appellate lawyer. Since joining Debevoise, Judge Gleeson has tried and argued commercial litigation matters in numerous federal and state trial courts and courts of appeals, appeared in multiple bankruptcy proceedings, acted as both a mediator and arbitrator in commercial and employment disputes, conducted independent investigations, advised boards of directors on corporate governance matters, and provided expert testimony on United States and New York law in multiple foreign tribunals. When he is not trying cases himself, he acts as litigation advisor to trial teams from others firms as their trials approach.

Prior to joining the firm, Judge Gleeson was a United States District Judge in the Eastern District of New York, sitting in Brooklyn. While a judge, Judge Gleeson authored more than 1,500 published opinions (including 14 opinions for the United States Court of Appeals for the Second Circuit, sitting by designation). He also presided over more than 200 civil and criminal jury trials. He was assigned numerous Multidistrict Litigations, including two antitrust class actions against Visa and MasterCard and the Air Cargo antitrust cases. Judge Gleeson served on the Judicial Conference Committee on Defender Services for nine years (including three years as Chair). The Defender Services Committee is responsible for the approximately $1 billion per year program that provides effective defense counsel to the 80% of federal defendants who cannot afford to retain counsel.

Before his appointment to the bench in 1994, Judge Gleeson was a federal prosecutor in the same courthouse for ten years. He served as Chief of the Criminal Division, Chief of Special Prosecutions, Chief of Organized Crime, and Chief of Appeals. He personally tried 20 cases to verdict, argued 25 appeals in the United States Courts of Appeals for the Second Circuit, and also argued appeals in Third and Sixth Circuits. Among the numerous high-profile cases he tried, Judge Gleeson was the lead prosecutor in the separate murder and racketeering convictions of John Gotti and Victor Orena, the bosses of the Gambino and Colombo Families of La Cosa Nostra, respectively. Judge Gleeson received the Attorney General’s Distinguished Service Award for his service in the Gotti case.

Judge Gleeson’s decade-long efforts to convict John Gotti, and his dismantling of the Mafia in New York, are depicted in his book The Gotti Wars: Taking Down America’s Most Notorious Mobster (Scribner 2022).

Prior to becoming a federal prosecutor, Judge Gleeson was a litigation associate at Cravath, Swaine & Moore for four years and a law clerk for the Hon. Boyce F. Martin, Jr. on the United States Court of Appeals for the Sixth Circuit.

Judge Gleeson has taught law for 35 years. He has taught Complex Federal Investigations at Harvard Law School and Sentencing at New York University School of Law and Yale Law School. He was the John A. Ewald, Jr. Distinguished Visiting Professor of Law at the University of Virginia School of Law. He has guest lectured at Yale Law School, Columbia Law School, Stanford Law School, Cornell Law School, University of Michigan Law School, Fordham Law School, Brooklyn Law School, and Cardozo School of Law.

Judge Gleeson is a founding co-author of the widely used treatise Federal Criminal Practice: A Second Circuit Handbook (LexisNexis), which is now in its 23rd edition. In her Foreward to the Tenth Edition, Justice Ruth Bader Ginsberg described the treatise as “a gift for judges in the Second Circuit,” a “labor of love” that she was pleased is “available to all who compose the bar and bench of ‘my’ circuit.”

In addition to being a fellow of the American College of Trial Lawyers, Judge Gleeson is a member of the American Law Institute, a member of the Advisory Boards of the Program on Corporate Compliance and Enforcement and the Center on Civil Justice at NYU School of Law, and a member of the Board of Directors of the Federal Defenders of New York.

Judge Gleeson is Co-chair of Debevoise’s Pro Bono Committee. In addition, he founded and runs The Holloway Project at Debevoise, a pro bono project dedicated to obtaining sentencing relief for inmates who were subjected to what the Chair of the Criminal Law Committee of the Judicial Conference of the United States called in 2009 one of the “most egregious mandatory minimum provisions” in the federal system, which produced “the unfairest, harshest, and most irrational results”: the enhanced consecutive sentences mandated by 18 U.S.C. § 924(c). As of April 2024, more than 70 Debevoise lawyers working with The Holloway Project had obtained sentence reductions for 56 clients around the country. The average sentence reduction is more than 40 years.

Judge Gleeson’s other publications include “Debevoise’s Holloway Project and ‘Second Looks’: How Challenging One Discrete Racial Inequity in Federal Criminal Justice Can Help Produce Systemic Change,” 33 Federal Sentencing Reporter 319 (2021); “Jack B. Weinstein Up Close,” 33 Federal Sentencing Reporter 160 (2021); "Judicial Scrutiny of NPAs and DPAs,” (Chapter in The Guide to Monitorships, Global Investigations Review (2019); “The Ulysses Cases and What They Reveal About Lawyers and the Law,” James Joyce Quarterly (2015); a chapter titled “Objections” in Winning at Trial: Insights From the Bench and Leading Litigators (2014); “The Sentencing Commission and Prosecutorial Discretion: The Role of Courts in Policing Sentencing Bargains,” Hofstra Law Review (2008); “The Road to Booker and Beyond: Constitutional Limits on Sentence Enhancements,” Touro Law Review (2006); “Supervising Federal Capital Punishment: Why the Attorney General Should Defer When U.S. Attorneys Recommend Against the Death Penalty,” Virginia Law Review (2003); “Supervising Criminal Investigations: The Proper Scope of the Supervisory Power of Federal Judges,” Journal of Law and Social Policy (1997); “Sentence Bargaining Under the Guidelines,” Federal Sentencing Reporter (1996); and “The Federalization of Organized Crime: The Advantages of Federal Prosecution” (with Dean John C. Jeffries, Jr.), Hastings Law Journal (1995).

Judge Gleeson’s awards include the following: The American Lawyer Lifetime Achievement Award (2023); Career Public Service Award, The Fund for Modern Courts (2022); The Thomas Jefferson Foundation Medal in Law, University of Virginia (2016) (the highest honor the University confers); The Gould Award for Outstanding Oral Advocacy, Office of Appellate Defender’s First Monday in October (2019); The National Legal Aid and Defender Association’s Exemplar Award (2018); Honorary Doctor of Laws, Northern Kentucky University (2016); The Distinguished Jurist in Residence, Cornell Law School (2016); The Distinguished Jurist Award, Defense Association of New York (2016); The Judicial Recognition Award, National Association of Criminal Defense Lawyers (2015); The Hon. William Brennan Award for Outstanding Jurist, New York State Association of Criminal Defense Lawyers (2014); The Green Bag Exemplary Writing Award, for United States v. Dossie (2013); The Green Bag Exemplary Writing Award, for United States v. Ovid (2011); and The Hon. Edward Weinfeld Award, New York County Lawyers’ Association (2008).

Judge Gleeson earned his J.D from the University of Virginia School of Law in 1980 and his B.A. from Georgetown University in 1975.

Recent speaking engagements include:

  • Speaker, Panel on Needed Criminal Justice Reform, Ninth Circuit Judicial Conference, Portland, Oregon, August 2023
  • Speaker, “Prosecuting ‘The Teflon Don’,” Third Circuit Bench and Bar Conference, Philadelphia, Pennsylvania, May 2023
  • Speaker, “Second Looks in the Courtroom,” Frankel at 50: A Half-Century’s Perspective on Criminal Sentences: Law Without Order, New York City Bar Association, April 2023
  • Moderator, Eleventh Annual Federal Criminal Practice Update, Federal Bar Association, March 2023, Central Islip, New York
  • The Leslie H. Arps Memorial Lecture, New York City Bar Association May 2022, New York, New York
  • Federal Sentencing Policy and Practice, ABA White Collar Crime Conference, October 2021
  • Guest Lecturer, Federal Criminal Law, Yale Law School, November 2021


  • University of Virginia School of Law, 1980, J.D.
  • Georgetown University, 1975, B.A.

Bar Admissions

  • New York