About John

John Campion has advised clients in corporate, family enterprise, regulatory and government matters for more than 45 years, appearing in court, before tribunals, and in arbitration and mediation. He has served as counsel in over 300 reported trials, hearings, appeals and judicial reviews, and has arbitrated more than 20 commercial disputes. Called to the bar in Ontario in 1974, he later gained admission in the Northwest Territories, New Brunswick, Nova Scotia, British Columbia, Manitoba, Quebec and Alberta. He earned his JD from the University of Toronto in 1972, later completing advanced mediation training at Harvard in 2015. John has represented clients before courts in ten provinces, the Federal Court and the Supreme Court of Canada, in matters spanning England, Europe, Asia and the United States. He served as an elected Bencher of the Law Society of Upper Canada and as President of the Federation of Law Societies of Canada, and has written and lectured widely on professional liability.

Practice areas

Civil Litigation & Dispute Resolution Business & Corporate Law

Education & credentials

Law school
University of Toronto
Undergraduate
University of Western Ontario, BA (1967)

Listing compiled from public sources in August 2026. Confirm John A. Campion’s licence and standing in the Law Society of Ontario directory ↗