Mary M. Thomson

One of Canada's pre-eminent litigators, Mary Thomson serves as head of Gowling WLG's national Litigation & Dispute Resolution Group and is past leader of its Product Liability Group. Over the past three decades, she has represented clients in many of the country's highest-profile legal matters in her field of expertise, including class actions and mass tort litigation, public inquiries, and before administrative tribunals.

Mary has appeared in courts across Canada on matters involving product liability, particularly involving pharma and medical devices as well as consumer products generally. She is a recognized expert in health law, consent law, privacy law and related matters.

Mary has been repeatedly singled out as a top legal practitioner by Chambers Canada, Canadian Legal Lexpert Directory, The Best Lawyers in Canada and other leading directories. In 2013, she was awarded the prestigious Lexpert Zenith Award for her extraordinary leadership in the legal profession.

In addition to her legal practice, Mary has taught trial advocacy and negotiation theory throughout her career. For more than a decade, she was an adjunct professor in the graduate department of the Faculty of Medicine at the University of Toronto, instructing in ethical and legal issues related to health law.

Mary is past chair of Outward Bound International (2011-2017), and was previously chair of Outward Bound Canada. She has chaired the Selection Committee (ON) for Pearson College, a United World College, for many years.

Career & Recognition

Filter timeline:
  • 2018

  • 2017

  • 2016

  • 2015

    • Rankings & Awards
      December2015
      Who’s Who Legal: Canada 2015
    • Rankings & Awards
      December2015
      Lexpert/ROB Special Edition on Canada's Leading Litigation Lawyers
    • Rankings & Awards
      November2015
      Expert Guides: Women in Business Law 2015
    • Rankings & Awards
      November2015
      Chambers Canada 2016
    • Rankings & Awards
      October2015
      LMG Life Sciences 2015
    • Rankings & Awards
      September2015
      The Best Lawyers in Canada 2016
    • Rankings & Awards
      September2015
      The International Who's Who of Business Lawyers 2015
    • Rankings & Awards
      July2015
      Benchmark Litigation's Top 25 Women in Litigation (Canada) 2015
    • Rankings & Awards
      July2015
      Canadian Legal Lexpert Directory 2015
    • Rankings & Awards
      May2015
      Who’s Who Legal: Life Sciences 2015
    • Rankings & Awards
      April2015
      Benchmark Canada: The Definitive Guide to Canada’s Leading Litigation Firms & Attorneys 2015
  • 2014

    • Rankings & Awards
      December2014
      Lexpert recognizes Gowlings professionals as leading litigation lawyers
    • Rankings & Awards
      November2014
      Expert Guides: Women in Business Law 2014
    • Rankings & Awards
      November2014
      LMG Life Sciences 2014
    • Rankings & Awards
      October2014
      Who's Who Legal: Canada 2014
    • Rankings & Awards
      September2014
      Who’s Who Legal: The International Who’s Who of Business Lawyers 2014
    • Rankings & Awards
      September2014
      Benchmark Litigation's Top 25 Women in Litigation (Canada)
    • Rankings & Awards
      September2014
      The Best Lawyers in Canada 2015
    • Rankings & Awards
      July2014
      Canadian Legal Lexpert Directory 2014
    • Rankings & Awards
      April2014
      Benchmark Canada: The Definitive Guide to Canada’s Leading Litigation Firms & Attorneys 2014
    • Rankings & Awards
      April2014
      Who's Who Legal: The International Who's Who of Life Sciences Lawyers 2014
  • 2013

    • Rankings & Awards
      December2013
      Lexpert 2013 Guide to the Leading US/Canada Cross-border Litigation Lawyers in Canada
    • Rankings & Awards
      December2013
      Expert Guides: Women in Business Law 2013
    • Rankings & Awards
      November2013
      Who's Who Legal: Canada 2013
    • Rankings & Awards
      September2013
      The Best Lawyers in Canada 2014
    • Rankings & Awards
      September2013
      Who's Who Legal: The International Who's Who of Product Liability Defence Lawyers 2013
    • Rankings & Awards
      August2013
      LMG Life Sciences 2013
    • Rankings & Awards
      July2013
      Canadian Legal Lexpert Directory 2013
    • Rankings & Awards
      July2013
      Who's Who Legal: The International Who's Who of Business Lawyers 2013
    • Rankings & Awards
      March2013
      Benchmark Canada 2013
    • Rankings & Awards
      February2013
      The Best Lawyers in Canada® 2013
  • 2012

    • Rankings & Awards
      December2012
      Who's Who Legal: Canada 2012
    • Rankings & Awards
      December2012
      2012 Lexpert® Guide to the Leading U.S./Canada Cross-Border Litigation Lawyers
    • Rankings & Awards
      July2012
      Canadian Legal Lexpert Directory 2012
    • Rankings & Awards
      July2012
      Who's Who Legal: The International Who's Who of Business Lawyers 2012
    • Rankings & Awards
      June2012
      PLC Which Lawyer? 2012
    • Rankings & Awards
      April2012
      Benchmark Canada 2012
    • Rankings & Awards
      February2012
      The Best Lawyers in Canada 2012
    • Rankings & Awards
      February2012
      Lexpert®/American Lawyer Guide to the Leading 500 Lawyers in Canada 2012
  • 2011

    • Rankings & Awards
      December2011
      Who’s Who Legal 2011
    • Rankings & Awards
      May2011
      Who's Who Legal - The International Who's Who of Business Lawyers , 2011
    • Rankings & Awards
      March2011
      PLC Which Lawyer? 2011
    • Rankings & Awards
      February2011
      The Best Lawyers in Canada® 2011
    • Rankings & Awards
      February2011
      Canadian Legal Lexpert Directory , 2011
  • 2010

    • Rankings & Awards
      February2010
      Expert Guides, 2010
    • Rankings & Awards
      February2010
      Canadian Legal Lexpert Directory , 2010
    • Rankings & Awards
      February2010
      The Best Lawyers in Canada® 2010
    • Rankings & Awards
      February2010
      PLC Which Lawyer? Yearbook , 2010
    • Rankings & Awards
      2010
      Who's Who Legal, Product Liability Defence
  • 1983

    • Qualifications (Year of Call/Admission, etc.)
      1983
      Year of Call, Ontario
  • 1981

    • Education
      1981
      Queen's University, LLB
  • 1980

    • Education
      1980
      University of New Brunswick, MA
  • 1977

    • Education
      1977
      University of New Brunswick, BA (Hons.)
    • Rankings & Awards
      Fellow, Litigation Counsel of America

Memberships

  • American Society of Law, Medicine & Ethics
  • Canadian Bar Association
  • Canadian Institute for the Administration of Justice
  • Defense Research Institute
  • The Advocates' Society

Mary has authored a number of articles and papers on a variety of topics, including contributing a chapter to Law and Ethics in Biomedical Research: Regulation, Conflict of Interest, and Liability, published by University of Toronto Press, 2006, and Lies, Damned Lies and Statistics: The Use of Statistical Evidence in Criminal and Civil Law, published in the proceedings of the Canadian Institute for the Administration of Justice, 2000.

Mary is a sought-after speaker in her areas of legal expertise.

Class Actions

  • Lead counsel for a major pharmaceutical client with respect to a diabetes medication.
  • Lead counsel for the manufacturer of a leading dental adhesive.
  • Lead counsel for major standards organization with respect to modular home claims.
  • From 2004 to 2009, lead counsel for a major pharmaceutical client with respect a leading coxib medication.
  • Lead counsel and national coordinating counsel for a major pharmaceutical client with respect to bisphosphonate litigation based in Saskatchewan.
  • Lead counsel for a leading energy drink manufacturer.
  • Lead counsel in a tuberculosis notification case including successfully defeating plaintiffs' claims for mental distress.
  • Lead counsel on a major privacy breach class action for a public entity.
  • Senior counsel to local litigation teams on diagnostic-related class actions, responsible for strategy and outcomes on class certification matters.

Mass Torts

  • Counsel to all physicians in Canada with respect to Krever Inquiry and "blood litigation" throughout the 1990s.
  • Trial counsel on Canadian litigation involving transfusion associated AIDS and related HBV, HCV claims.
  • Responsible for product recall and patient notification regarding surgical instrumentation and possible transmission of infectious diseases.
  • Act for a number of manufacturers of medical devices and pharmaceutical products with respect to threatened litigation.