Kevin J. O’Brien is a Senior Partner with Marks, O’Neill, O’Brien, Doherty & Kelly and serves as the Managing Director of the Philadelphia office. He is admitted to practice in Pennsylvania, New York, New Jersey, U.S. Court of Appeals of Third Circuit, U.S. District Court for the Eastern District of Pennsylvania and U.S. District Court for the District of New Jersey. He is a member of the American, Pennsylvania, and Philadelphia Bar Associations. He is also a member of the Friends of St. Malachy Inc. and the University of Scranton President’s Business Counsel and Disciplinary Board of Supreme Court of Pennsylvania Hearing from 2007-2013 and 2016-present.

Kevin graduated from the University of Scranton in 1980, with a Bachelor of Science. Later, he attended Seton Hall University School of Law, graduating in 1983.

Kevin has been called upon to implement case management systems and train lawyers in various jurisdictions on effective trial techniques in the mass tort setting. He has also been called upon as a lecturer to various groups, including continuing legal education classes and industry training seminars, on trial tactics and strategy. Kevin currently serves as National Coordinating Counsel for several defendants in asbestos litigation. He is also involved as Regional Trial Counsel for several clients. Kevin has been called upon to litigate asbestos cases in a wide variety of venues.

Since founding Marks O’Neill in 1986, Kevin has concentrated his practice in the defense of complex matters involving toxic tort, pharmaceutical products and medical devices. He is also actively involved in the defense of claims arising out of commercial transactions. Kevin has been involved in toxic tort matters for over twenty years. He has extensive experience in asbestos, silica, benzene, diet drugs and medical device litigation. Kevin continues to have an active practice in the areas of commercial litigation. The role that Kevin holds provides counsel to business clients concerning contract negotiation, human resource issues and dispute resolution. He is also involved with the litigation of a vast array of business and commercial disputes both in the State and Federal Courts, as well as in alternative dispute resolution settings. Kevin’s practice has a significant component of representing employers in their disputes with employees. This includes proceedings before the Equal Employment Opportunity Commission (EEOC) and Pennsylvania Human Relations Commission (PHRC).

Kevin J. O'Brien

Phone 215-832-4217

Kevin J. O'Brien PDF


  • J.D., Seton Hall University School of Law, 1983
  • B.S., University of Scranton, cum laude, 1980

Bar Admissions

  • Pennsylvania, 1983
  • New Jersey, 1983
  • New York, 2005
  • U.S. Court of Appeals Third Circuit, 1984
  • U.S. District Court for the Eastern District of Pennsylvania, 1983
  • U.S. District Court for the District of New Jersey, 1983

Bar Associations

  • American Bar Association
  • Pennsylvania Bar Association
  • Philadelphia Bar Association

Practice Areas

  • Casualty Group
  • Employment Law, Municipal & Public Entity
  • Construction Accident/Construction Defect
  • Toxic Tort, Mass Tort, Environmental and Products Liability

Representative Cases