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John T. Duffey


3300 Wells Fargo Center, 90 South Seventh Street, Minneapolis, MN 55402-4140

Bar Admissions

U.S. District Court
  • Minnesota
  • E.D. Michigan

Leadership & Community

  • Maslon UPLIFT: Legal Institute for Teens
  • Minnesota State Bar Association
  • Hennepin County Bar Association


John Duffey represents clients in complex commercial litigation matters, including business torts and contract disputes, with a particular emphasis on noncompete, trade secret, and financial services litigation. John helps clients navigate all stages of the litigation process and has significant experience representing large and small businesses in all forums: federal and state courts, arbitrations, and mediations.

John earned his bachelor's degree in history from Duke University in Durham, North Carolina. He earned his law degree, cum laude, from the University of Michigan Law School in Ann Arbor, Michigan. During law school, he served as editor-in chief of the University of Michigan Journal of Law Reform and was the recipient of the Jeffrey S. Lehman Legal Practice Award and the Sarah Honigman Memorial Award.


  • Obtained multimillion-dollar judgment for regional accounting firm in noncompete dispute with former partner.
  • Secured TROs and preliminary injunctions for medical device manufacturer in actions to enforce noncompetes and other restrictive covenants.
  • Represented national banking association in litigation and bankruptcy matters concerning its role as indenture trustee for revenue bond offerings.
  • Defended dental practice management company with respect to breach of contract and breach of fiduciary duty claims brought in multiple states.
  • Managed e-discovery and related issues in numerous federal and state court actions.


Recognized on Minnesota Rising Stars list as part of the Super Lawyers® selection process, 2020 (Minnesota Rising Stars is a designation given to only 2.5 percent of Minnesota attorneys each year, based on a selection process that includes the recommendation of peers in the legal profession.)


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