Mark O'Donnell

Mark M. O'Donnell graduated in 1979 from McMaster University (Honours Bachelor of Commerce (Summa Cum Laude) and Osgoode Hall Law School (1982). Mark was called to the Bar in Ontario in 1984 and is an Associate of the Insurance Institute of Canada (1989 with Honours) and a Chartered Insurance Professional. He has throughout practised in the defence of insurance interests and in the defence of insurers. Mark is a founding partner of O'Donnell, Robertson & Partners.

Practice Focus:

  • Insurance coverage litigation in all areas of insurance law, representing the interests of insurers. Extensive litigation experience involving significant and complex disputes.
  • Casualty and property insurance related matters.
  • Bodily injury related litigation.
  • Defence of errors and omissions claims brought against professionals.
  • Defence of product liability and occupiers liability related claims.
  • Subrogation recovery claims on behalf of insurers.
    • Acting for domestic and foreign primary and excess insurance carriers in the defence of insured claims and in coverage disputes.
  • Defence of sexual abuse claims against institutions.
  • Extensive trial and appellate experience as counsel in various insurance-related matters in Ontario.
  • Advisor to leading Canadian insurers with respect to cases involving multi-party toxic tort claims, environmental litigation and insurance coverage matters. Co-ordinating counsel in connection with the defence of numerous toxic tort and environmental claims brought against insureds throughout the United States.
  • Counsel work in the area of re-insurance recovery.
  • Extensive experience in alternative dispute resolution involving arbitration and mediation.
  • Drafting legal opinions on the subject of various types of insurance-related issues and providing advice with respect to policy drafting, interpretation and application.


  • Law Society of Upper Canada
  • Insurance Institute of Canada
  • Associate Member of the Insurance Council of Canada
  • Chartered Insurance Professional Society
  • Defence Research Institute
  • Canadian Defence Lawyers Association
  • Canadian Bar Association
  • President of the Oakville Speed Skating Club