Jon G.Heintz


Washington + 1.202.879.3819

Jon Heintz represents commercial clients in complex civil litigation in federal trial and appellate courts. He also has represented clients before the U.S. Judicial Panel on Multidistrict Litigation (JPML), the International Court of Arbitration, and various federal regulatory agencies.

Jon has experience in many different types of litigation matters, including corporate mergers challenged by state and federal antitrust enforcers, nationwide consumer products class actions, First Amendment claims, and general commercial disputes. He also has extensive experience defending against claims asserted under the federal Fair Credit Reporting Act (FCRA), including class claims. Jon has been involved in these matters at each stage of litigation, including devising litigation strategy; dispositive and class certification motions practice; fact, expert, and class discovery; trial; and appeal.

Throughout his career, Jon has represented clients in diverse industries, including health care, insurance, aviation/aerospace, credit reporting, consumer goods, and media.

In addition, Jon maintains an active pro bono practice, including briefing and arguing a matter before the U.S. Court of Appeals for the Third Circuit.


  • National Review prevails in high-profile defamation caseJones Day secured a favorable ruling at summary judgment for defendant National Review, Inc., in a long-running and high-profile defamation case brought by climate scientist Dr. Michael Mann.
  • Parker Hannifin defends $4.3 billion acquisition of CLARCORFollowing a post-closing antitrust investigation, Parker Hannifin Corporation retained Jones Day to act as antitrust counsel in its litigation with the U.S. Department of Justice (DOJ) Antitrust Division over the company’s $4.3 billion acquisition of CLARCOR Inc.
  • PinnacleHealth System and Penn State Hershey attempt to merge Pennsylvania hospitalsJones Day represented PinnacleHealth System and Penn State Milton S. Hershey Medical Center as antitrust counsel in the hospitals' proposed merger.