Atty. Jack O'Neill

Atty. Jack O'Neill

Jack O'Neill has been trying large complex cases for over 45 years. His experience in the courtroom involves many cases that have been widely publicized.

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Profile Summary

About Jack O'Neill at a glance

Jack O'Neill is a business, litigation, environmental, appellate, and energy attorney based in Houston, Texas, practicing at Pierce & O'Neill LLP. Admitted to practice in Texas, State Bar of Texas. Educated at The University of Texas (J.D., 1972) and University of Pennsylvania (B.A.). Recognitions include Best Lawyers in America — Appellate Practice (2026), Best Lawyers in America — Commercial Litigation (2026), and Best Lawyers in America — Natural Resources Law (2026). Serands clients in Houston, TX and the surrounding metropolitan area.

Verified attorney profile · Updated June 2026

About

  • Jack O'Neill has been trying large complex cases for over 45 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 multi-million 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
  • 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, Inc., Stewart & Stevenson Services, Inc., 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, Inc., 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

Practice Areas Explained

Jack O'Neill's Areas of Practice

Each practice area below reflects the types of cases Jack O'Neill handles, with a brief overview of what that area of law covers.

Business & Corporate Law

Business attorneys advise founders and growing companies on entity formation, contracts, financing, M&A, and dispute resolution.

Jack O'Neill is one of 501,317 business attorneys indexed nationally. Browse business attorneys in Texas →

Civil Litigation

Civil litigation attorneys for breach of contract, business disputes, civil rights, and class action lawsuits.

Jack O'Neill is one of 454,532 litigation attorneys indexed nationally. Browse litigation attorneys in Texas →

Environmental Law

Environmental attorneys for regulatory compliance, contamination, land use, and natural resource law.

Jack O'Neill is one of 56,434 environmental attorneys indexed nationally. Browse environmental attorneys in Texas →

Appellate Practice

Appellate attorneys for civil and criminal appeals at state and federal court.

Jack O'Neill is one of 86,319 appellate attorneys indexed nationally. Browse appellate attorneys in Texas →

Energy & Utilities Law

Energy attorneys for oil & gas, renewables, utility regulation, and energy sector transactions.

Jack O'Neill is one of 36,230 energy attorneys indexed nationally. Browse energy attorneys in Texas →

Jurisdictional Context

Why local counsel matters in Texas

Practicing law in Texas. Legal matters in Texas are governed by state-specific rules of civil and criminal procedure, statutes of limitations, and substantive law. Cases originating in Houston are typically filed in the local municipal court or the appropriate Texas state district court, depending on subject matter and amount in controversy. An attorney licensed in Texas brings working knowledge of local procedural deadlines, judicial practices in this andnue, and the substantive law that applies to cases brought here. Out-of-state attorneys generally cannot represent clients in Texas courts without local counsel or pro hac vice admission.

Looking for additional Texas attorneys? Browse all attorneys in Houston or all attorneys in Texas.

Frequently Asked

Common questions about Jack O'Neill

Where is Jack O'Neill's law office located?
Jack O'Neill's law practice is located in Houston, Texas. The firm is Pierce & O'Neill LLP. You can contact the office directly through this profile page.
What practice areas does Jack O'Neill handle?
Jack O'Neill focuses on business, litigation, environmental, appellate, energy. Each practice area listed reflects experience handling cases of that type in Texas.
Where did Jack O'Neill go to law school?
Jack O'Neill earned their education at (J.D., 1972); (B.A.).
How can I contact Jack O'Neill for a consultation?
You can contact Jack O'Neill directly through this profile page. Click "Ask the Attorney" to submit a question, or "Schedule a Consultation" to book a meeting. Most claimed-profile attorneys respond within one business day.
What awards or recognition has Jack O'Neill received?
Jack O'Neill's notable recognition includes: Best Lawyers in America — Appellate Practice; Best Lawyers in America — Commercial Litigation; Best Lawyers in America — Natural Resources Law; Best Lawyers in America — Oil and Gas Law; Best Lawyers in America — Additional Areas of Practice:.

Education

J.D.
The University of Texas
- 1972
B.A.
University of Pennsylvania
- In Progress

Awards

Best Lawyers in America — Appellate Practice
- 2026
Best Lawyers in America — Commercial Litigation
- 2026
Best Lawyers in America — Natural Resources Law
- 2026
Best Lawyers in America — Oil and Gas Law
- 2026
Best Lawyers in America — Additional Areas of Practice:
- 2026
Best Lawyers in America — Arbitration
- 2026
Best Lawyers in America — Awards:
- 2026
Best Lawyers in America — Lawdragon 500 Leading Litigators in America, 2022-2026
- 2026
Best Lawyers in America — Lawdragon 500 Leading Lawyers in America, 2024-2025
- 2026
Best Lawyers in America — Lawdragon 500 Leading Energy Lawyers, 2025
- 2026
Best Lawyers in America — Lawdragon Hall of Fame, 2025
- 2026
Best Lawyers in America — Texas Super Lawyers, Thomson Reuters, 2003-2025
- 2026
Best Lawyers in America — Chambers USA
- 2026
Best Lawyers in America — among the leading Commercial Litigation attorneys, 2024-2025
- 2026
Best Lawyers in America — Martindale-Hubbell "AV" Rating
- 2026

Bar Admissions

Texas, State Bar of Texas

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