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Nancy Gellman is one of the founders of Conrad O’Brien and serves as the firm’s vice chair. Her extensive practice experience spans a broad array of matters, including complex commercial litigation, class action, insurance coverage cases, antitrust, professional liability, and employment litigation. Nancy is recognized as a leading trial lawyer, including being named a Fellow of the American College of Trial Lawyers and highly rated by Chambers USA: America’s Leading Lawyers for Business. She is also listed in Best Lawyers in America (for Commercial Litigation, Antitrust, Legal Malpractice Law – Defendants, and Bet-the-Company Litigation).  


In addition to her litigation practice, Nancy has lectured on trial advocacy for the Pennsylvania Bar Institute, the Philadelphia Defense Institute, the Philadelphia Bar Association’s Trial Advocacy Program, and Temple University Law School’s L.L.M. in Trial Advocacy Program. She also taught appellate advocacy for several years at the University of Pennsylvania Law School.


Yale Law School, J.D.

Bryn Mawr College, A.B.

London School of Economics, Fulbright Fellowship


The Honorable Joseph S. Lord, III, former Chief Judge, United States District Court for the Eastern District of Pennsylvania


  • Pennsylvania

  • U.S. District Court for the Eastern District of Pennsylvania

  • U.S. District Court for the Middle District of Pennsylvania

  • U.S. Court of Appeals for the Third Circuit

  • Supreme Court of the United States


"She's very good on her feet, has a lot of gravitas and credibility in court, and is very thoughtful."

Chambers USA 2022

"She has a wealth of litigation experience and advises on a broad range of commercial disputes."

Chambers USA 2020

"She is a brilliant trial lawyer with superb intellectual prowess. Her writing and critical thinking have been instrumental in all the matters we have been involved with."

Chambers USA 2017

Honors & Affiliations

  • Fellow, American College of Trial Lawyers; Chair, Pennsylvania State Committee (2016–2018)

  • Selected as a Leading Lawyer for General Commercial Litigation in Chambers USA, The Client’s Guide to America's Leading Lawyers for Business (2003–present)

  • Listed in Best Lawyers in America for Commercial Litigation, Bet-The-Company Litigation, Litigation - Antitrust, and Legal Malpractice Law – Defendants (2001–present)

  • Named 2018 Philadelphia Legal Malpractice Law – Defendants “Lawyer of the Year” by Best Lawyers in America

  • Listed in Benchmark Litigation, Top 250 Women in Litigation

  • Listed as a "Local Star" in Benchmark Litigation, Guide to America's Leading Litigation Attorneys

  • AV® Preeminent™ Peer Review Rated by Martindale-Hubbell

  • Listed in Pennsylvania Super Lawyers (2004–present)

  • Listed on the Top 50 Women Lawyers List by Pennsylvania Super Lawyers (2004–present)

  • Listed on the Top 100: Pennsylvania Lawyers List in Pennsylvania Super Lawyers (2020)

  • Listed on the Top 100: Philadelphia Lawyers List in Pennsylvania Super Lawyers (2021-present)

  • American Law Institute

  • Bryn Mawr College Alumnae Association Executive Board, Secretary (2021-present)

  • Yale Law School Association - Vice President (2011–2013), Executive Committee (2009–2011, 2016-2019)

  • Drexel University Kline School of Law - Member, Law School Board (2013–present)

  • Fellow, American Bar Foundation

  • American Bar Association

  • Philadelphia Bar Association

  • Served as Judge Pro Tem, Court of Common Pleas, Philadelphia County

  • Served as Mediator, U.S. District Court for the Eastern District of Pennsylvania