Sonia Bjorkquist - Litigation Lawyer

Sonia Bjorkquist

Partner, National Chair, Litigation

Chair: Corporate and Commercial Litigation

Key Contact: Product Liability

Key Contact: Class Action Defence

Key Contact: Domestic and International Arbitration

Key Contact: Privacy Litigation

Key Contact: International Trade and Investment

Contact Information

tel: 416.862.5876



Sonia is Chair of the firm’s National Litigation Department and Past President of the Advocates’ Society. Sonia has extensive experience defending companies in class actions, commercial arbitration and other complex litigation, including advising clients on strategies for managing risks and cross-border issues in multi-jurisdictional cases. She defends complex product liability claims across many industries. She litigates business-critical issues related to commercial agreements, banking, construction, data and privacy, directors' duties and shareholder remedies.

An “extremely dedicated” and “tireless advocate” and trial lawyer, Sonia is ranked among Canada’s top litigators in Chambers Global (Dispute Resolution: Class Action Defence, and Litigation: Product Liability and General Commercial), Lexpert/ALM 500, Lexpert (Class Actions, Product Liability Litigation, Corporate-Commercial Litigation, and Commercial Arbitration), Best Lawyers (Class Action Litigation and Product Liability Law), and a Benchmark Litigation Star. Best Lawyers named Sonia as “Lawyer of the Year” for Product Liability Law, Toronto (2019). She is named as a leader in class actions in the Lexpert Guide to the Leading US/Canada Cross-Border Litigation Lawyers in Canada. Sonia is rated AV Preeminent in Martindale Hubbell’s Peer Review Ratings. She is a frequent speaker and author on class action and commercial arbitration issues.

Sonia was selected by the Government of Canada as a delegate to the CUSMA Advisory Committee on Private Commercial Disputes in accordance with USMCA Article 31.22, and served on the predecessor NAFTA 2022 Advisory Committee. The CUSMA Advisory Committee promotes the use of arbitration, mediation and ODR for the prevention and resolution of international commercial disputes between private parties in the North American free trade area.

Prior to joining Osler as a lawyer, Sonia clerked for the Court of Appeal for Ontario.

    • Advising a world leading construction and services company in disputes resulting from the design-build-finance of numerous projects connected to a major Ontario infrastructure project
    • A leading multinational pharmaceutical company in defending product liability class actions and individual actions in several jurisdictions
    • A leading medical device company in defending product liability class actions and individual actions in several jurisdictions
    • A multinational auto manufacturer in regulatory investigations regarding diesel emissions
    • A Canadian oil company in proceedings arising from the Lac-Mégantic rail disaster
    • A leading data company in private commercial arbitration over a long-term supply agreement
    • A leading manufacturer of automotive parts in a long private arbitration involving a long-term supply agreement
    • A leading environmental technology company defending product liability claims regarding the design and engineering of waste treatment equipment
    • A refinery in a long Ontario trial defending environmental contamination claims
    • A multinational dairy company in litigation with an ingredient supplier following a national Class I recall
    • The Receivers of Stanford International Bank in proceedings regarding the forfeiture of funds related to an international fraud and ponzi scheme
    • A major chartered bank in defending allegations of negligence and misrepresentation in individual and proposed class proceedings in three jurisdictions
    • The directors and officers of a bankrupt company in a New Brunswick class action involving allegations of breach of fiduciary duty in respect of the administration of company pension plans
    • A manufacturer of power transmission and distribution equipment in a long New Brunswick trial involving complex breach of warranty and negligence, including successfully defending an appeal taken to the Court of Appeal
    • A technology company in a long Ontario trial involving claims by a former senior executive for lost stock options
    • A leading financial processing services company in a long trial defending claims by a former chief executive officer
    • A private investment company in a long Ontario trial arising from a breached share purchase transaction, and successfully defending appeals taken to the Ontario Court of Appeal and Supreme Court of Canada
    • Public and private sector organizations as respondents and affected third parties in access to information, investigations and hearings

  • Chambers Canada: Canada’s Leading Lawyers for Business: Recognized in Litigation: Products Liability (Nationwide); Dispute Resolution: Class Action (Defence) (Nationwide); Litigation: General Commercial (Ontario)
  • The Canadian Legal Lexpert Directory: Recognized in Class Actions; Commercial Arbitration; Litigation - Corporate Commercial; Litigation - Product Liability
  • The Lexpert/American Lawyer Guide to the Leading 500 Lawyers in Canada: Recognized in Litigation – Product Liability
  • Best Lawyers in Canada: Recognized in Class Action Litigation; Corporate and Commercial Litigation; Product Liability Law
  • Who’s Who Legal: Recognized in Product Liability Defence (Global; Canada); Life Sciences - Product Liability (Global; Canada); Life Sciences (Global; Canada); Litigation (Canada); Commercial Litigation (Global)
  • Benchmark Litigation Canada: Recognized in Arbitration; Class Actions; Dispute Resolution (Litigation Star)
  • Thomson Reuters: "Stand-out Lawyer"
  • Litigation Counsel of America: Fellow

  • Osler Pro Bono Community Law, international human rights matters and Canadian civil liberties matter

  • CUSMA Article 31.22 Advisory Committee On Private Commercial Disputes
  • The Advocates’ Society, Executive Committee, Immediate Past President
  • Federation of Defense and Corporate Counsel (FDCC), Elected Member
  • Defence Research Institute (DRI) Member
  • Toronto Commercial Arbitration Society (TCAS), Member, Past Member of Executive Committee
  • Young Canadian Arbitration Practitioners (YCAP), Advisory Board, Past Member of Board of Directors and Past Vice-President
  • ADR Institute of Canada, Past Member of Board of Directors
  • Canadian Bar Association (Ontario), Member
  • American Bar Association Member, Litigation Section
  • International Bar Association, Member
  • Toronto Lawyers Association, Member
  • Trial Law Institute, Member
  • Diversity Law Institute, Member

  • Sources of Ethical Obligations in International Arbitration, LexisNexis Canada Inc., May 2021 (co-authored). 
  • Push and Pull in Class Proceeding Standards North of the Border: Re-Evaluating Preferable Procedure Requirements in Canadian Class Actions, Federation of Defense and Corporate Counsel (FDCC) Class Action and Multi-District Litigation Newsletter, March 2020 (co-authored).
  • International Commercial Dispute Resolution:  How it’s different and how understanding the differences can help your practice, FDCC Annual Meeting, Switzerland, 2017 (co-authored).
  • New Frontiers: The Oversight Role of Courts in Common Law Canada, Colloque National sur  l’action Collective, Barreau du Quebec, 2017 (co-authored).
  • Expect the Unexpected:  The Changing Landscape of Class Proceedings, Colloque National sur  l’action Collective, Barreau du Quebec, 2016 (co-authored).
  • The Oppression Remedy, Canada Law Book, loose leaf -- updated annually since 2004 (co-authored with D. Morritt and A. Coleman).
  • Getting to the Merits: Developments in Class Action Procedure in Common Law Canada, 2014,Colloque National sur les Recours Collectifs, Barreau du Québec, March 2015 (co-authored).
  • Drafting Dispute Resolution Clauses (co-authored), June, 2015.
  • Arbitration Advocacy, Advocates’ Society, November 28, 2014 (co-chair).
  • Is Canada ripe for a food label fight? The Lawyers Weekly, November 26, 2014 (co-authored).
  • Taking Stock of Product Liability Food Claims in Canada, Law360, August 7, 2014 (co-authored).
  • Class actions for exaggerated health claims on the rise: report, by David Dias, Legal Feeds (Blog of Canadian Lawyer and Law Time), August 7, 2014.
  • Just Enough:  Practical Boundaries of Certification, Colloque National sur les Recours Collectifs, Barreau du Québec, March 2014 (co-authored).
  • Class Action Waivers Different From Arbitration Agreements? Osler Canadian Class Action Defence Blog, November 22, 2013 (co-authored).
  • Interviewed in The Law Times, “Are Class Actions Going to Trial More Often?” by Julius Melnitzer, September 2, 2013.
  • The Class of 2012: Where Are We Now?, Colloque National sur les Recours Collectifs, Barreau du Québec, March, 2013 (co-authored).
  • Class Actions in Canada 2012, Osler, Hoskin & Harcourt LLP, January 30, 2013 (co-authored).
  • Multi-Jurisdictional Classes: Does Van Breda Change Anything?, OBA Class Acts, Vol. 3, No. 1, December 2012 (co-authored with M. Paterson).
  • Litigating a Cross-Border Class Action in Canada, ALM Cross-Border Litigation Forum, New York, September 12, 2012.
  • The New Emergency Arbitration Rules of the ICC, CBA National Section on International Law Newsletter, April 2012 (co-authored with E. Morgan).
  • Ethical Challenges in Arbitration Advocacy, Advocates’ Society Arbitration Advocacy, March 27, 2012 (Speaker).
  • Multi-jurisdictional Class Actions: Will the New CBA and ABA Protocols Solve all our Problems? Développements Récents en Recours Collectifs, Barreau du Québec, Vol. 345, March 2012 (co-authored with M. Eizenga and M. Paterson) (Speaker).
  • The Class Action Landscape for 2012: What In-House Counsel Needs to Know, Osler, Hoskin & Harcourt LLP, January 25, 2012 (Speaker).