Mark R.Seiden

Of Counsel

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Mark Seiden has successfully represented clients in product liability, commercial litigation, and complex civil litigation in courts throughout the United States. Since 2010, he has served as trial counsel in more than a dozen jury trials.

Mark's representation of R.J. Reynolds Tobacco Company spans more than a decade and includes a wide variety of cases including putative class actions, third-party payor lawsuits, individual product liability cases, marketing and unfair practices claims, and alleged international money laundering.

On behalf of Macy's, Mark led a Jones Day team that successfully opposed — both at the trial and appellate courts — a request for certification of a nationwide class of vendors pressing claims under UCC Article 2. On behalf of IBM, he successfully argued before the New York Court of Appeals that alleged soil and groundwater contamination did not constitute a material breach of a commercial lease. He also represented IBM on a number of insurance coverage matters.

In addition, Mark has significant experience representing asset-based lenders, including factors and accounts receivable (A/R) financiers.

Mark is deeply committed to working on pro bono matters. He has developed deep experience in international child abduction matters, representing parents in Europe, South America, Mexico, and the Caribbean. Mark has served as practice coordinator for the office's New Lawyers Group for more than half a decade.

Mark is an adjunct professor of law, teaching a pretrial practice seminar at Cardozo Law School.


  • Employers at Hunts Point Produce Market reach agreement with Teamsters after week-long strikeJones Day served as lead negotiator for the association of employers at the Hunts Point Produce Market in its 2020-2021 collective bargaining negotiations with Teamsters Local 202 and provided support during a resulting week-long strike.
  • R.J. Reynolds prevails in U.S. Supreme Court on geographic scope of Civil RICOJones Day successfully represented the petitioners in a major U.S. Supreme Court decision restricting the extraterritorial application of the Racketeer Influenced and Corrupt Organizations Act (RICO).
  • ACI Worldwide wins declaratory judgment granting all requested relief in software licensing disputeJones Day client ACI Worldwide Corp. ("ACI") won a declaratory judgment granting all of ACI's requested relief against defendant Churchill Lane Associates, LLC ("Churchill") in a case arising from a dispute between the parties concerning software licensing royalties.
  • Pro bono team wins motion to dismiss for lack of personal jurisdiction for Indie Rock BandA team from Jones Day New York obtained dismissal of a complaint against three Chicago performing artists, brought by the former manager of their band.
  • R.J. Reynolds wins jury verdict in Anderson ''Engle progeny'' lawsuitOn January 24, 2014, a jury in state court in Tampa, Florida returned a verdict in favor of Jones Day client R.J. Reynolds Tobacco Company in a wrongful death case finding that the decedent smoker was not an Engle class member.
  • Jones Day attorneys successfully represent U.S. Air Force servicemember wrongfully named in child support suitD.W., a Senior Airman in the U.S. Air Force, received a summons from the New York Department of Social Services ("DSS") to appear at a child support hearing in New York County (Manhattan) Family Court.
  • Jones Day attorneys secure return of child to mother in Dominican Republic pursuant to the Hague Convention on the Civil Aspects of International Child AbductionFive-year-old E.M.H.B (the "Child") was returned to his mother in the Dominican Republic on January 17, 2014 after being wrongfully retained by his father in Perth Amboy, New Jersey since January 3, 2013.
  • R.J. Reynolds wins jury verdict in Frailey ''Engle progeny'' lawsuitOn June 28, 2012, after almost three weeks of trial, a state court jury in Jacksonville, Florida returned a verdict in favor of Jones Day client R.J. Reynolds Tobacco Company.
  • NACCO resolves claims against Harbinger hedge fundsIn 2006, Applica Incorporated terminated its merger agreement with Jones Day client NACCO Industries, Inc. in favor of a competing offer from the Harbinger hedge funds.
  • Father ordered to return sons to mother in UKFollowing a four-day bench trial in the Eastern District of New York earlier in 2010, Jones Day New York attorneys Lauri Sawyer, Jonathan Muenkel, Caryn Wolfe, Matt Chow and Eric Jacobi successfully reunited a mother in England with her two children who had been wrongfully detained in New York.
  • R.J. Reynolds wins jury verdict in Budnick ''Engle progeny'' lawsuitJones Day successfully represented R.J. Reynolds Tobacco Company in an "Engle progeny" lawsuit.
  • Father succeeds in the return of his four-year old son, who had been abducted by his mother and taken to New York City, to the Cayman IslandsOn December 5, 2008, Jones Day New York filed suit on behalf of Mr. W in the United States District Court for the Eastern District of New York, seeking the immediate return of his four-year-old son to the Cayman Islands under the Hague Convention on International Child Abduction after the son was abducted by the child's mother and taken to New York.
    • December 5, 2019
      Federal Bar Council Presents: Expert Witnesses