Gregory W. Lyons

Gregory W. Lyons focuses his practice on handling both prosecution and defense in complex commercial litigation. He has represented clients ranging from major corporations to individuals and small businesses, guiding them through disputes with precision. His litigation work spans contract conflicts, tort disputes, insurance coverage matters, and class action litigation.

Greg received his Bachelor of Arts degree, magna cum laude, from the University of Wisconsin–Whitewater. He later completed his Juris Doctor at Marquette University Law School.

His strong academic background has been the foundation for a career built on tenacity, legal insight, and a commitment to serving clients effectively in courtrooms across the country.

Greg also has extensive experience in inheritance litigation, where he has represented clients in will contests, trust disputes, and complex estate conflicts. He has guided trustees, personal representatives, and powers of attorney through high-stakes disputes, often involving intricate family and financial issues. His ability to manage emotionally charged cases while achieving strong outcomes has made him a trusted advocate.

Greg has appeared in both state and federal courts across numerous jurisdictions, including Florida, Oregon, Texas, Illinois, California, Washington, D.C., Arizona, and New York. His admissions include Wisconsin state and federal courts, the Seventh Circuit Court of Appeals, and the United States Supreme Court. Beyond litigation, he provides general business counseling and appellate advocacy, offering clients well-rounded legal support.

Gregory W. Lyons also serves as Chairperson of his firm’s Ethics Committee, reflecting his dedication to integrity and professional responsibility. With a career defined by skill in complex litigation and inheritance disputes, he has built a record of achieving favorable results for those he represents. His combination of trial experience, appellate advocacy, and ethical leadership demonstrates his strength as a reliable and determined legal advocate.

Law Office Affiliations

• Attorney, O’Neil, Cannon, Hollman, DeJong & Laing S.C.
• Life Fellow, American Bar Foundation
• Member, State Bar of Wisconsin
• Member, Eastern District of Wisconsin Bar Association
• Member, Milwaukee Bar Association
• Member, Waukesha County Bar Associaton
• Member, Ozaukee Bar Association
• Member, Waukesha County Business Alliance
• Member, Defense Research Institute
• Member, Independent Business Association of Wisconsin

Licensed State

• Wisconsin

Education

• Marquette University Law School
  Juris Doctor (JD)
• UW Whitewater
  BA with Magna Cum Laude

Awards & Badges