Class Action Defence

Wooden tray filled with black marbles with one hole missing.

Osler’s Class Actions Defence Practice Group has successfully defended clients in many of the leading and complex class action cases in Canada. We specialize in developing multi-faceted national class action defence strategies and, when necessary, co-ordinating with U.S. counsel to supplement and execute a cohesive, solution-focused North American defence strategy. We also have an excellent track record in opposing and defeating class certification and winning early dismissals in every major jurisdiction in Canada. This practice includes mandates across a wide range of areas including: product liability, consumer protection (Québec's Consumer Protection Act), privacy, securities, environmental, false or misleading advertising, pensions and benefits, employment and franchise.

Our class action team is experienced in guiding clients through the most complex business-critical challenges. We offer:

  • Risk mitigation – We work proactively with clients to develop risk management strategies to avoid claims whenever possible and to be “litigation ready” when claims are commenced. Osler will rapidly mobilize the right team to assist in minimizing the impact of a class action through immediate management of processes and documents, aggressive early assessment and planning, probable risk assessment, budget controls and crisis communications.

  • National co-ordinating trial counsel – Our lawyers serve in the role of national counsel across Canada and are able to respond to cases simultaneously across the country, including in Québec, where civil rules apply. We have ongoing experience in leading and co-ordinating multijurisdictional, U.S. and international cases.

  • Unmatched research capabilities – The research requirements for effective defence of a class action can be complex and detailed. Osler’s Research Department provides sophisticated support leading to precedent-setting results.

  • Thought leadership – Our work has been instrumental in establishing leading principles of class action law, including the right of a defendant to defer the filing of a defence until after certification; the right to conduct examinations of representative plaintiffs in aid of certification; the nature of evidence to be filed on certification; the rules regarding solicitation of class members by plaintiff’s solicitors; and the necessity of considering the merits of the claim as part of the certification process.

  • Discovery management – Our discovery management specialists have extensive experience in delivering customized, cost-effective and efficient discovery solutions in complex multijurisdictional class actions.


Sonia Bjorkquist

Partner, National Chair, Litigation


Mary Buttery, KC

Partner, Litigation


Laura Fric

Partner, Litigation


Deborah Glendinning

Partner, Litigation


Tristram Mallett

Partner, Litigation


Christopher Naudie

Partner, Litigation


Éric Préfontaine

Partner, Litigation


  • Facebook Inc.

    Facebook Inc. in the successful dismissal of the plaintiff’s appeal from an order denying certification of a proposed class action

  • Facebook, Inc.

    Facebook, Inc. in the successful dismissal of certification of a proposed class action

  • BP p.l.c.

    BP p.l.c. in Kaynes v BP

  • Hydro One Inc.

    Bennett v. Hydro One Inc. et al

  • BP

    BP p.l.c. in a securities class action arising from the 2010 Deepwater Horizon explosion

  • GuestLogix Inc.

    GuestLogix Inc. in proposed securities class action alleging misrepresentations contained in company’s public disclosures relating to certain credit facilities

  • Manulife

    Manulife in a proposed class action commenced in British Columbia relating to the distribution of mortgage insurance products by Manulife’s wholly-owned subsidiary, Benesure Canada Inc.

  • Boston Scientific Ltd. and Boston Scientific Corporation

    Boston Scientific Ltd. and Boston Scientific Corporation in fifteen individual matters in three provinces, as well as a certified class action in Ontario and three proposed class actions in other provinces (Saskatchewan, Alberta, Quebec)

  • Facebook, Inc.

    The BC Court of Appeal stayed a privacy class action in Douez v. Facebook, Inc. by enforcing a forum selection clause in favour of the courts of California. In a narrow 4-3 judgment, the SCC overturned the decision.

  • Cadbury Adams Canada Inc.

    Cadbury Adams Canada Inc. in 14 class actions across Canada arising from a regulatory investigation into the pricing and sale of chocolate confectionary products in Canada.

  • Elpida Memory Inc.

    Elpida Memory Inc. in an indirect purchaser class action related to alleged price fixing regarding DRAM.

  • E.I. DuPont Canada Company

    E.I. DuPont Canada Company in a class action involving pricing and distribution arrangements with independent distributors.

  • Amex Bank of Canada

    Amex Bank of Canada in six class actions alleging various breaches of Québec’s Consumer Protection Act and constitutional challenges.

  • Toronto-Dominion Bank

    Toronto-Dominion Bank in certification appeals and settlement of a class action seeking damages for fees applied to foreign exchange transactions on TD Visa credit cards.

  • Vale Inco Limited

    Vale Inco Limited in a class action on behalf of residents of the City of Port Colborne, alleging property damages related to historic emissions from Inco’s nickel refining activities.

  • Vale Inco Limited

    Vale Inco Limited in a class action arising from an accidental gas emission from one of the company’s facilities.

  • Canada Mortgage and Housing Corporation

    Canada Mortgage and Housing Corporation in a class action relating to pension surplus.

  • Hydro-Québec

    Hydro-Québec where a class action by retirees claiming pension surplus was dismissed.

  • Michelin North America (Canada) Inc.

    Michelin North America (Canada) Inc. in successfully resisting an appeal relating to contribution holidays and plan administration.

  • Dell Canada Inc.

    Dell Canada Inc. in the Supreme Court of Canada on the ability of companies to oust the provincial class actions regime in favour of a commercial arbitration.

  • Eli Lilly Canada Inc. and Eli Lilly & Company

    Eli Lilly Canada Inc. and Eli Lilly & Company in defence of four proposed class actions in Ontario, Québec, British Columbia and Alberta on claims relating to alleged side effects of an antipsychotic drug.

  • Imperial Tobacco

    Imperial Tobacco in the successful defence of the largest proposed class action in Canada brought on behalf of all current and former smokers in Ontario.

  • Microsoft Corporation

    Microsoft Corporation in a class action regarding billing practices for Internet access services provided by the Microsoft Network. The court upheld an exclusive jurisdiction clause in the “click wrap” licence agreement that each individual must accept before using the service.

  • Procter and Gamble

    Procter and Gamble, whose branded pet food products were manufactured by Menu Foods Limited and distributed in Canada.

  • State Farm Mutual Automobile Insurance Company

    State Farm Mutual Automobile Insurance Company in two separate proposed class actions relating to: (1) the use of non-original equipment manufactured parts in insured repairs; and (2) the applicability of an insured's deductible when a vehicle is written off and salvaged.

  • Find More

  • Chambers: Canada’s Leading Lawyers for Business: Recognized in Dispute Resolution: Class Action (Defense)
    • One source says the firm is "great at high-level strategy. I've been impressed with the way they've been able to advocate seriously but also have a respectful relationship with co-defendants or counsel."
  • The Canadian Legal Lexpert Directory: Recognized in Class Actions (Toronto, Ontario; Montreal, Quebec)
  • Benchmark Litigation Canada: Osler lawyers recognized in Class Action