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Daphne O'Connor, co-chair of the firm's Product Liability Litigation practice group, focuses her practice on managing, litigating, and trying complex product liability and mass tort cases. She has served as national counsel for major pharmaceutical and tobacco companies with a focus on legal strategy, settlement, and complex scientific and medical issues. She also counsels clients on litigation risks, U.S. Food and Drug Administration (FDA) regulatory issues, including on tobacco, hemp and cannabis, and the litigation and compliance impacts of potential legislation.

Daphne rejoined the firm after having served for seven years as Vice President and Associate General Counsel for Altria Client Services, Inc. In that role, she managed all aspects of commercial and product liability litigation, including trials and appeals in both state and federal courts throughout the country. She handled a diverse portfolio of cases including personal injury and consumer fraud, class actions and large consolidations, tax refund, patent, antitrust, contract, environmental, and regulatory cases. She also coordinated major settlements.

Daphne has a deep commitment to pro bono representation and civil rights issues, and has represented individuals in civil Section 1983 lawsuits, employment discrimination lawsuits, prison conditions cases, and in criminal cases. She is on the Chair's Roundtable of the Colorado Lawyers Committee and has served on the University of Colorado Law School Alumni Board.


  • Philip Morris USA Inc. in the management and defense of thousands of smoking and health actions brought by individual plaintiffs in dozens of Florida jurisdictions following the decertification of a high-profile class action. Engle Progeny Litigation (numerous Florida State and Federal Courts) (2015-present)
  • Wyeth in all facets of state and federal litigation in defense of products liability suits. During this representation, Daphne served as trial counsel in Conlon et al v. Wyeth (Phila. Cty. Ct. Com. Pleas January 2007).In re Diet Drugs (2001-2008)
  • Wyeth in all aspects of litigation including as trial counsel in Daniel v. Wyeth (Phila, Cty. Ct. Com. Pleas, March 2005).In re Hormone Replacement Products Liability Litigation (2004-2008)


BTI Consulting Group Names Five Arnold & Porter Attorneys as 2023 'BTI Client Service All-Stars'
FDA Preemption of Conflicting State Drug Regulation and the Looming Battle Over Abortion Medications
Journal of Law and the Biosciences, Volume 10, Issue 1
Legal and Practical Issues in Cannabis Regulation
Food and Drug Law Institute
BTI Consulting Group Names Nine Arnold & Porter Attorneys as 2020 'BTI Client Service All-Stars'
CBD-Infused Cosmetics: A Comprehensive Legal Overview
Speaker, Personal Care Products Council Webinar


The Legal 500 U.S.
"Leading Lawyers" Dispute Resolution: Product Liability, Mass Tort and Class Action: Consumer Products (including tobacco) (2023)
Product Liability, Mass Tort and Class Action: Consumer Products (including tobacco) (2021-2022)
Product Liability, Mass Tort and Class Action: Pharmaceuticals and Medical Devices — Defense (2021-2022)
Product Liability, Mass Tort and Class Action: Toxic Tort — Defense (2021-2022)
Cannabis (2021)
Chambers USA
"Spotlight Table" Product Liability: Tobacco (Nationwide) (2022-2023)
"Leading Litigator" — Product Liability (2022)



  • J.D., University of Colorado Law School, 1994, Order of the Coif
  • A.B., Duke University, 1989


  • District of Columbia
  • Florida
  • U.S. Court of Appeals for the Tenth Circuit
  • U.S. District Court, District of Columbia
  • U.S. District Court, District of Colorado
  • Supreme Court of the United States


  • Lecturer in Law, Drug Product Liability Law, Columbia Law School