John Massaro litigates class actions and other complex commercial disputes. His experience includes handling high-profile matters involving billions of dollars in alleged damages as well as more discreet matters implicating legislative or regulatory inquiries, transactional solutions, or alternative dispute resolution. Mr. Massaro's focus is on solving problems.

Mr. Massaro is Chair of the firm's Risk Committee. He also currently serves as Adjunct Professor of Law at George Mason University School of Law, teaching Federal Courts. Prior to joining the firm, Mr. Massaro was law clerk to the Honorable Bruce M. Selya of the US Court of Appeals for the First Circuit.


  • Co-lead counsel in one-week jury trial relating to valuation of shares in a privately held company. Result: verdict for client.
  • Represented private equity fund in six-week jury trial of alleged fraud, breach of duty, and malpractice against officers and professionals of a portfolio company. Result: verdict for client.
  • Lead counsel for private equity fund in arbitration of dispute with insurance company over coverage for complex commercial claim. Result: payment of claim.
  • Represented consumer product manufacturer in 10-week jury trial involving RICO and product liability allegations. Result: substantial verdict for client followed by victory on appeal.
  • Lead counsel for publicly held investment company in arbitration hearing relating to disputes arising out of purchase of manufacturing company. Result: award for client.

  • Lead counsel for publicly held investment company in arbitration hearing relating to fraud and indemnification claims. Result: award for client.
  • Lead counsel in arbitration hearing and related litigation relating to disputes over commodities contracts. Result: following award, case settled on favorable terms for client.


The Legal 500 US
Product Liability, Mass Tort and Class Action: Consumer Products (including tobacco) (2013, 2015, 2017, 2022)
Corporate Governance (2018)
Washington, DC Super Lawyers
Business Litigation, Class Action/Mass Torts, and Securities Litigation (2012-2016)


  • JD, Harvard Law School, 1992, magna cum laude
  • BA, Williams College, 1989, magna cum laude
  • District of Columbia
  • New York
  • Numerous Federal Courts
  • United States Court of Appeals, First Circuit, The Honorable Bruce M. Selya

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