Drawing on more than five decades of courtroom experience, Dennis R. Suplee regularly serves as a AAA mediator and arbitrator in a wide range of complex commercial disputes. A former Regent of the American College of Trial Lawyers and past President of the International Academy of Trial Lawyers, Dennis has litigated a host of civil matters, including antitrust and RICO cases, commercial disputes, trademark and patent cases, insurance coverage litigation and product liability claims.

Prior to joining Welsh & Recker, Dennis spent 56 years with Schnader Harrison Segal & Lewis, where he served as firm chair from 1992 to 1998. Dennis is also the lead co-author of The Deposition Handbook, a leading resource for attorneys and the definitive text on taking and defending depositions, the first edition of which was published in 1988 and the sixth edition of which will be published later this year.

Dennis has been listed in Best Lawyers for bet-the-company, commercial litigation, environmental litigation and intellectual property litigation; Chambers USA for commercial litigation; and the International Who’s Who of Commercial Litigation. He is a past president of the University of Pennsylvania Law School’s Inn of Court and has frequently written on pretrial and trial practice and the legal profession throughout the course of his career.

Representative Matters

  • Secured a $72.5 million award on behalf of his client in an AAA case involving the alleged breach of an agreement to settle patent infringement claims.
  • Successfully represented UPS in two high-profile cases before the U.S. Department of Transportation, including a dispute over air-operating rights between the U.S. and Japan, then valued at $100 million per year.
  • Appointed by a federal judge to represent the families of 45 deceased players facing a statute of limitations defense to the recovery of monetary benefits in the NFL Concussion Litigation.
  • Prosecuted a CERCLA contribution action on behalf of the owner of a battery-breaking facility against more than 250 battery suppliers. The case represents the first time that a court allocated liability to a scrap battery supplier where the owner-operator was financially viable.
  • Secured a preliminary injunction on behalf of Villanova University in a lawsuit to prevent its former booster club from using the names “The Wildcat Club” and “Villanova Alumni Educational Foundation” after more than 20 years of doing so without a written licensing agreement.
  • Represented STERIS as a plaintiff in a patent infringement case involving hydrogen peroxide gas vaporizers used by pharmaceutical companies and others for bio-decontamination of instruments and rooms. After two months of discovery, defendant stipulated to the entry of an Order prohibiting it from marketing its infringing product. Because such vaporizers are used to counter the threat of bioterrorism, the victory was a significant one for the client.
  • Prosecuted and defended legal malpractice claims.


  • American College of Trial Lawyers, Regent for PA, NJ and DE, 2001-2005; Pennsylvania State Chair, 1998-2000
  • The Foundation of the American College of Trial Lawyers, Board of Directors, 2006-2009
  • International Academy of Trial Lawyers, President, 2009-2010
  • University of Pennsylvania Law School American Inn of Court, President, 2009-2012