John Tancabel is a trial lawyer who handles high-stakes, complex business disputes in state and federal court as well as in arbitration. John has extensive experience representing owners of privately held companies in disputes with their co-owners, including asserting and defending fiduciary duty, fraud, breach of contract and securities-related claims. Additionally, he has significant experience in multijurisdictional matters and in defending class action claims, and has helped defeat class certification in many cases.

Prior to joining the firm, John practiced law at a national corporate law firm, where he acted as the co-chair for the company’s business divorce practice. Out of law school, he served as a judicial law clerk for the Honorable Judge Sidney A. Fitzwater, who was the Chief Judge of the US District Court for the Northern District of Texas at the time.

While attending law school, John acted as the associate managing editor for the SMU Law Review Association. John later graduated as the salutatorian of his class and was inducted into the Order of the Coif.

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  • Southern Methodist University Dedman School of Law, J.D., summa cum laude, Salutatorian, Order of the Coif, 2007
  • University of Dallas, B.A., summa cum laude, 2002


  • Texas, 2007


  • U.S. Dist. Ct., N. Dist. of Texas
  • Listed in The Best Lawyers in America 2021-2024 for Commercial Litigation

  • Co-author, “Heritage Prevails: The Texas Supreme Court's Royalty Calculation Jurisprudence After Burlington,” Oil, Gas & Energy Resources Law, December 2019.
  • Co-Author, “Business Divorce Chapter,” Texas Business Litigation Treatise, 2017.
  • Co-Author, “How Low Can You Go? An Insiders’ Perspective on Selectica v. Versata and NOL Poison Pills,” Securities Regulation Law Journal Vol. 39, June 2011.
  • Co-Author, “Director and Officer Fiduciary Duties in the Context of Insolvency,” Presented at the State Bar of Texas 8th Annual Advanced In-House Counsel Course, Chapter 11, July 2009.
  • Author, “Reflections on the McNulty Memorandum,” Securities Regulation Law Journal Vol. 35, Fall 2007.

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