Jonathan D.Guynn (Jon)


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Jon Guynn focuses his practice on complex commercial litigation, internal investigations, and white collar defense. He has represented individuals and companies in a broad range of industries, including aerospace, clinical laboratory diagnostics, utilities, telecommunications, biopharmaceuticals, financial services, metals and mining, home health care, medical devices, food and beverage, and digital advertising. He regularly represents clients in connection with complex and sensitive internal investigations and government inquiries arising, among others, under the False Claims Act (FCA), Foreign Corrupt Practices Act (FCPA), and federal and state securities laws.

Jon has successfully defended corporations and their directors and officers in civil, criminal, and regulatory disputes where plaintiffs sought hundreds of millions of dollars in claimed damages or penalties. He routinely represents clients opposite qui tam relators' counsel, the U.S. Department of Justice, and other federal or state agencies.

Jon has a wealth of complex litigation experience, with an emphasis on health care, securities, trade secret, and antitrust litigation. He has participated in and managed many aspects of litigation, from case inception through resolution, including conducting internal investigations, motion practice, fact and expert discovery, taking and defending depositions, and examining witnesses at trial.

Jon counsels clients regarding corporate disclosure and compliance with securities and health care regulation, with an emphasis on environmental, social, and governance (ESG) issues.

Jon is also an active pro bono lawyer. He successfully represents asylum applicants, prisoners seeking to vindicate their religious liberties, and victims of domestic violence in obtaining restraining orders and custody of minors, among others.


  • U.S. Chamber of Commerce, coalition challenge OSHA Walkaround Inspection RuleJones Day filed a complaint on behalf of a coalition of industry groups, led by the U.S. Chamber of Commerce, challenging the Occupational Safety and Health Administration's (OSHA) Worker Walkaround Representative Designation Process rule.
  • Exxon Mobil pursues declaratory judgment action against shareholder proposalJones Day is representing Exxon Mobil Corporation in seeking a declaratory judgment that it may exclude from its proxy statement under SEC Rule 14a-8 a shareholder proposal from activist organizations Arjuna Capital and Follow This that calls for targets to reduce Scope 1, 2, and 3 greenhouse gas emissions.
  • Members of Congress file amicus brief in religious liberty caseJones Day filed an amicus brief in the U.S. Supreme Court, on behalf of several dozen members of Congress, in support of a football coach who was fired from his job as a public high school educator because he refused to stop engaging in a brief private prayer on the football field after games.
  • Beneficient Company Group acquires shares in GWG Holdings, Inc.Jones Day advised The Beneficient Company Group, L.P. (BEN), a provider of liquidity products and services to the owners of alternative assets and illiquid investment funds, in its acquisition of shares in GWG Holdings, Inc. (GWG Holdings), a NASDAQ listed company that is a leading provider of liquidity to owners of life insurance in the secondary market, previously held by GWG Holdings’ founding stockholders, Jon R. Sabes and Steven F. Sabes.