John R. Byrne


John is a trial lawyer who handles every case with a view towards winning at trial. As both a former federal prosecutor and federal appellate law clerk, John brings both a cerebral and practical approach to case development and strategy. Given his philosophy and experience, it is no surprise that high-profile clients have trusted him with their cases, including a former head of state, a prominent NCAA head basketball coach, and high-level city and federal officials


John specializes in the litigation of complex commercial transactions and consumer fraud matters on behalf of both plaintiffs and defendants.

Prior to co-founding Maderal Byrne PLLC, he was an Assistant United States Attorney for the Southern District of Florida. During his time at the U.S. Attorney’s Office, John charged over 60 cases, including numerous fraud cases. He took 16 of these cases to trial, serving as first chair ten times and second chair six times. During his time as a prosecutor, he developed an extensive knowledge of federal law, including federal statutory law, the Federal Rules of Evidence, and the Federal Rules of Criminal Procedure.

John also has extensive federal appellate experience. In addition to having argued appeals before multiple United States Courts of Appeal, he served as the law clerk to Judge Jeffrey R. Howard of the U.S. Court of Appeals for the First Circuit.

Prior to his time as an Assistant U.S. Attorney, John practiced with Ropes & Gray LLP, where he focused on internal investigations, regulatory enforcement matters, and complex commercial disputes.


  • Obtained a $66 million award for alternative energy client following a three week arbitration hearing in Chicago. Proved that wind turbine manufacturer supplied client with defective wind turbine blades.

  • Represented a Latin American former head of state in extradition proceedings, obtained an order releasing said individual on bond and dealt with numerous issues of first impression.

  • Represented energy company in fraud action in federal court, resulting in a $10 million settlement.

  • Represented prominent former NCAA basketball coach in connection with federal investigation arising out of Southern District of New York. No charges filed.

  • Represented former State Department official in connection with high-profile federal lawsuit in the Southern District of Florida, successfully obtaining protective order governing his testimony.


J.D., Cornell Law School, cum laude, 2007
B.A., University of Florida, cum laude, 2002


Hon. Jeffrey R. Howard, U.S. Court of Appeals for the First Circuit


A Change in Character: The Amendment to Federal Rule of Evidence 404(b), The Daily Business Review (2021)

Demystifying the Civil Deposition, The Federal Lawyer (2021)

The Rise of the Net Impression Test in Fla. Consumer Suits, Law 360 (2020)


Federal Bar Association, South Florida Chapter, Board of Directors

Riverside House, Chair of Young Professionals Board

Florida Bar’s Eleventh Circuit Judicial Circuit Grievance Committee

Contact Us

If you need our help, call or email us any time for a free case evaluation.

– OR –

Send an email below: