About William Michael
William Michael Cannon trained as a historian before turning to law. He earned a B.A. in history from Marquette University in 1969 and completed his J.D. at the University of Wisconsin–Madison in 1972. Those academic foundations feed into a legal career that spans decades and many courtrooms.
Early in his practice Cannon established himself in litigation. He is admitted to practice in Wisconsin and has credentials that allow him to appear in federal appellate courts, including the Seventh Circuit, and before the U.S. Supreme Court. Those admissions reflect a practice that has ranged from trial work to appellate advocacy.
Cannon has pursued formal recognition of his trial and professional liability skills. He is a Diplomate of the American Board of Professional Liability Lawyers and is board certified as a trial lawyer by the National Board of Trial Advocacy. Those certifications signify peers’ assessment of competence in courtroom work and professional liability matters. They also mark a professional path oriented toward contested cases and courtroom strategy rather than transactional work.
Over the years Cannon has handled cases that required both detailed factual development and careful legal argument. He has worked at every stage of litigation: pretrial investigation, motion practice, jury trial and appeals. His experience across these phases informs how he prepares cases and how he advises clients about risks, timelines and likely outcomes.
Association with Cannon & Dunphy places him in a law practice where litigation remains central. The firm listing ties his name to ongoing civil litigation and trial practice. Within that setting he continues to take on matters that call for courtroom experience, including complex disputes that involve questions of professional responsibility and liability.
Outside the courtroom he has maintained ties to legal organizations that set standards for trial practice and professional liability law. Those connections have kept him engaged with evolving rules of procedure and evidence, and with peers who try similar cases.
As of 2026 William Michael Cannon remains active in litigation. He continues to handle trials and appeals, concentrating on professional liability and trial-level disputes in state and federal courts.
