John Greffet

John Greffet is a trial lawyer at Sumner Law Group, LLC who handles complex personal injury and consumer claims. His practice includes car accidents, trucking crashes, wrongful death, premises liability, medical malpractice, and consumer protection. He represents clients from the initial investigation and claims process through trial and appeal, using more than a decade of litigation experience in federal and state courts in Missouri and Illinois.

John earned a B.S. in Political Science from Southern Illinois University-Edwardsville and a J.D. from Saint Louis University School of Law. His education prepared him for a practice centered on litigation, legal analysis, and advocacy for people facing serious injuries or disputed claims. That foundation supports his ability to evaluate liability, organize evidence, develop case strategy, and communicate legal issues clearly throughout each stage of a contested matter.

John has experience trying cases in state and federal courts and handling appellate matters. He works on claims involving unsafe driving, commercial vehicles, dangerous property conditions, medical negligence, wrongful death, and consumer issues. His approach emphasizes investigating the facts, holding responsible parties accountable, and guiding clients through the legal process from early claim development through settlement negotiations, courtroom proceedings, and post-trial or appellate work when necessary.

John Greffet is a member of The Missouri Bar, the Missouri Association of Trial Attorneys, the Bar Association of Metropolitan St. Louis, and the Illinois State Bar Association. His community involvement includes volunteering with the Holiday Hearts Program at Crisis Nursery St. Louis. By combining trial experience with direct client communication, he helps injured people understand their options and pursue practical legal remedies in difficult circumstances.

Law Office Affiliations

• Attorney, Sumner Law Group, LLC
• Member, The Missouri Bar
• Member, Illinois State Bar Association
• Member, Missouri Association of Trial Attorneys
• Member, Bar Association of Metropolitan St. Louis

Licensed State

• Missouri
• Illinois

Education

• Saint Louis University School of Law
  Juris Doctor (JD)
• Southern Illinois University-Edwardsville
  Bachelor of Science (BS) in Political Science

Awards & Badges