Jonathan is a co-founder and Managing Partner of Boies Schiller Flexner. He has led the firm’s recent expansion in London; Washington D.C.; and California. His substantial litigation successes for the firm include co-lead counsel for the class action plaintiffs in the In Re Vitamins antitrust litigation, which the presiding judge determined “uncovered the illegal actions of vitamins manufacturers across the globe,” and in which a record antitrust settlement of $1.05 billion was achieved for the class. Who’s Who Legal recognized Jonathan as one of its most highly regarded individuals, naming him “the real deal” in their listing of the top 10 international commercial litigators for 2011. Who’s Who Legal has continued to recognize him as an international leader in litigation through 2020.

In 2020, Jonathan led the successful defense of Barclays in U.S. federal District Court in securing dismissal of In re: ICE LIBOR Antitrust Litigation lawsuit. From 2012-2020, Jonathan led Barclay’s defense of the consolidated LIBOR Antitrust Litigation in U.S. Federal District Court in New York. From 2009-2018, Jonathan led the successful defense of Barclays in bankruptcy court in New York against a $13 billion claim from the Lehman Brothers Estate, stemming from its purchase of the North American operations of Lehman Brothers, and recovered in excess of $9 billion for Barclays through 2018, including most recently £250 million from Lehman in the LBIE litigation through London courts.

On behalf of the Baltimore Orioles, Jonathan successfully obtained the dismissal in 2019 of a lawsuit brought by the Washington Nationals against the Orioles seeking to enjoin an AAA arbitration commenced by the Orioles. On appeal, Jonathan secured a unanimous affirmation of the trial court’s ruling by the Appellate Division in 2019. He has successfully represented the New York Yankees in litigation against Major League Baseball and StubHub, and in disputes with the New York Attorney General during the period 2015-2019.

Jonathan successfully prosecuted an international arbitration claim in 2017 on behalf of OPAP in the Court of International Arbitration over the Greek state’s appropriation of valuable license rights in the Greek lottery.

Jonathan successfully represented claimants in an ICC proceeding in Zurich in a dispute concerning control of a Central European gaming company and breach by the respondent of the shareholder agreement. Following public evidence of allegations of the respondent’s corruption of public officials and the commencement of parallel criminal investigations against its officers, the arbitration was successfully concluded. Claimants were able to confirm their entire interest in and majority control over the gaming and casino company.

As appellate counsel in a high-profile divorce in New York, Jonathan achieved unanimous victories over attempts to confirm the fair and equitable trial court’s distribution of artworks valued at over $800 million.

Jonathan represents fantasy sports website DraftKings in various jurisdictions over the legality of the multibillion-dollar daily fantasy sports business. New York, Massachusetts, and other states subsequently legalized this activity.

Jonathan won a March 2014 FINRA arbitration award for Goldman Sachs in California that rejected $300 million in claims of fraud brought by co-founders of Marvell Technology Group Ltd. He successfully defended Goldman Sachs & Co in 2006 against New York Stock Exchange seat holders who sought to enjoin NYSE’s merger with Archipelago Holdings.

Jonathan was lead counsel in the successful defense of the Bank of New York Mellon against a $22.5 billion RICO claim brought by the Russian Federal Customs Service in the Moscow Arbitration Court. After two years of litigation, including a trial in Moscow, the case was settled for $14 million – less than 1 per cent of claimed damages. The result was hailed by the analyst community as a “grand slam home run.”

While maintaining full litigation and management responsibilities at BSF, Jonathan recently finished his five-year term as chair of the board of trustees of Columbia University. He is now Chair Emeritus.

Parallel Proceedings Involving International Arbitration, International Disputes Seminar, ICC, Los Angeles, California (October 1999)

Identifying and Applying the Law Governing the Arbitration Procedure - Role of the Law of the Place of Arbitration, A Commentary, ICCA Congress Series No. 9, Paris (May 1998)

Providing for Confidentiality in International Mediation, ICC Institute of International Business Law and Practice (October 1995)

Destruction of Grand Jury Documents, Destruction of Evidence (1989) (co-author)

Modification of Pension Fund Contributions During the Term of a Collective Agreement: The 1987 Employment and Economic Security Pact, 90 West Virginia Law Review 843 (1988)

The Legal Liability of Private Security Guard Company for the Criminal Act of Third Parties, An Overview, The Annals 91 (July 1988)

  • Columbia Law School, J.D.
  • Columbia University, B.A., Political Science; Chair, Columbia Board of Trustees (2013–present); Blue Key Honor Society; Ivy League Championship Basketball Team; Columbia University Athletics Hall of Fame


  • District of Columbia
  • New York
  • U.S. District Court: Southern District of New York
  • U.S. District Court: District of Colorado
  • U.S. Court of Appeals: Second Circuit
  • U.S. Court of Appeals: Third Circuit
  • U.S. Court of Appeals: Ninth Circuit
  • U.S. Court of Appeals: D.C. Circuit
  • U.S. Supreme Court

Chair, Columbia University Board of Trustees (2013–2018)

Medal of Excellence, Columbia Law School (2019)

Top Rated Lawyer by Martindale Hubbell (2020)

Inaugural Legend of Ivy League Basketball for “achievements and contributions to the Ivy League” (March 2017)

Alexander Hamilton Medal, the highest honor bestowed by the Columbia College Alumni Association (2012)

M. Klein & Company Advisory Board Member

Member of the Dean's Council of Columbia Law School

John Jay Award for Distinguished Professional Achievement (Columbia University 2006)

Board of Trustees, National Membership Chair, Supreme Court Historical Society, Washington D.C.

Board of Trustees, American Ballet Theater

Life Member, Fellows of the American Bar Foundation (2001)

Best Lawyers in America (2005-2024)

Super Lawyers (2008-2021)

Lawdragon 500 Hall of Fame

Lawdragon 500 Leading Litigators in America (2023-2024)

Lawdragon 500 Leading Lawyers in America (2006-2020)

Lawdragon 500 Global Litigation Lawyers Guide (2021, 2023)

Considered “one of the premier international arbitration attorneys in the world,” and "A seasoned practitioner with an impressive reputation," The US Legal 500

“Recognized as a leading practitioner in the field of international arbitration,” and a "real warrior, who will wade into any battle for you." Chambers USA 

Litigator of the Week, The AmLaw Litigation Daily (2011)

One of the most highly regarded individuals, “the real deal,” a Top Ten International Commercial Litigator, Who's Who Legal

Who’s Who Legal International (2010–2019)

Milan Chamber of Commerce International Arbitration Club of Arbitrators (1995-Present)

  • Hon. Charles R. Richey, U.S. District Court: District of Columbia