William J. O’Brien

BillWilliam J. O’Brien

Bill is a trial lawyer and has over 30 years of experience in a broad range of product liability, mass tort, class action, construction, insurance and commercial litigation. He has defended multiple companies in asbestos litigation and has acted as National Coordinating Counsel (NCC) for a number of clients.

Bill has had trial and supervisory responsibility for well over 100,000 cases and has tried cases involving hundreds of plaintiffs in jurisdictions throughout the country. In his capacity as NCC Bill has acted as a chief strategist and counselor in Mass Tort Litigation and has developed defense strategies and theories that have been adopted and implemented nationwide.

Bill is the founding and managing partner of the O’Brien Firm.

Professional Affiliations:

  • American Bar Association
  • Pennsylvania Bar Association
  • New Jersey Bar Association
  • District of Columbia Bar Association
  • Defense Research Institute


  • Catholic University of America (J.D., 1986)
  • Boston College (B.S., 1983)


  • Pennsylvania
  • New Jersey
  • New York
  • District of Columbia
  • U.S. District Court for the Eastern District of Pennsylvania
  • U.S. District Court for the District of New Jersey
  • U.S. District Court for the District of Columbia
  • U.S. Supreme Court