Jack O'Neill

Jack O'Neill

Pierce & O'Neill, LLP

Recognized since 2014

Houston, Texas

Practice Areas

Appellate Practice

Commercial Litigation

Oil and Gas Law

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Jack O'Neill has been trying large complex cases for over 39 years. His experience in the courtroom involves many cases that have been widely publicized. Mr. O'Neill was co-trial counsel for UPR, Inc. in its attempted takeover of Pennzoil. He was lead counsel for Mitchell Energy Corporation in the company's effort to overturn a $204 million judgment rendered against the company in a case tried for the company by another law firm. On appeal, argued by Mr. O'Neill, the case was reversed in its entirety and judgment was rendered in favor of Mitchell. He was lead trial counsel for Mitchell Energy in a related case in which plaintiffs sought $750 million for alleged contamination of their properties by natural gas and hydrogen sulfide. After a three-month trial, the jury rendered a unanimous verdict in favor of Mitchell. He was lead trial counsel for plaintiffs in the highly publicized Key 1-11 gas well blowout case in the Texas Panhandle, the largest blowout of a gas well in continental United States history. After a trial lasting over two and a half months, the jury returned one of the largest verdicts in Randall County, Texas history in favor of Mr. O'Neill's clients. He was lead trial counsel for a well-known Houston oil and gas company in a fraud case in which the plaintiff sought damages in excess of $100 million. After a two-month trial, the jury returned a verdict for Mr. O'Neill's client, and a take-nothing judgment was entered by the trial court. Mr. O'Neill has successfully tried many other cases relating to virtually all aspects of the oil and gas industry.

Mr. O'Neill's trial experience is not confined to oil and gas matters. He successfully defended GE in the "Desert Storm" Ramstein Air Base C-5A crash litigation. As co-counsel, he successfully defended GE in the trial court and before the Fifth Circuit and the United States Supreme Court in the U.S.S. Stark litigation, emanating out of the attack on the Stark in the Persian Gulf by an Iraqi fighter jet. He successfully defended Eastman Kodak Company in its mini-lab class action case, involving alleged damages of $3 billion. Mr. O'Neill was lead counsel for plaintiffs in a suit against an American subsidiary of a foreign trading company for employment discrimination against American citizens, which established in the district court and United States Supreme Court that American subsidiaries of foreign companies are not immune from United States fair employment laws. He has obtained a multimillion-dollar jury verdict for an equipment manufacturer in an unfair competition and theft of trade secrets case. As lead trial counsel, he successfully defended McKesson Corporation by obtaining a unanimous jury verdict in a trademark infringement trial in which the plaintiff sought damages in excess of $1 billion. As lead arbitration counsel, he successfully procured a unanimous arbitration opinion in favor of Weatherford International, Inc., granting Weatherford specific performance of a contract to convey computer software, denying in its entirety the defendant's counterclaim of over $100 million, and awarding Weatherford its attorney fees and expenses. He has also successfully defended a toy manufacturer in a trademark infringement trial. He has successfully defended a former United States Senator in litigation filed against a major United States company and its directors.

Mr. O'Neill has won numerous jury verdicts in cases involving allegations of breach of contract, negligence and gross negligence, trademark infringement, unfair competition, fraud, environmental contamination and strict liability. Over the years, his clients have included Exxon Mobil Corporation, UNOCAL, Koch Industries, Stewart & Stevenson Services, The Williams Companies, GE, Eastman Kodak Company, INVISTA, Anadarko Petroleum Corporation, The John Wood Group, CNA, Transcontinental Gas Pipe Line Corporation, Mitchell Energy & Development Corp., Devon Energy Corporation, McKesson Corporation, Weatherford International and many other Fortune 500 companies.

Mr. O'Neill is a former director of the Litigation Section of the State Bar of Texas. He is a member of the American Board of Trial Advocates. He is also a member of the International Association of Defense Counsel.


  • 4203 Montrose Boulevard
    Houston, TX 77006


  • The University of Texas, J.D., graduated 1972

Bar Admissions

  • Texas, State Bar of Texas


  • American Board of Trial Advocates - Member
  • International Association of Defense Counsel - Member
  • Texas Bar Foundation - Member

Recognized in The Best Lawyers in America® 2023 for work in:

  • Appellate Practice
  • Commercial Litigation
  • Oil and Gas Law


  • Selected for inclusion in Texas Super Lawyers, 2003-2015
  • Martindale-Hubbell® "AV" Rating
  • Selected for inclusion in Best Lawyers, 2014-2015

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