Corporate and Commercial Litigation

Dominoes in a curved line beginning to fall.

Osler’s litigation practice is one of the largest and most accomplished in Canada. Years of careful recruiting and rigorous training have allowed us to develop deep expertise in complex corporate and commercial litigation. As experienced trial and appeal lawyers, our litigators appear as counsel in all levels of courts in Ontario, Alberta, Québec and most other Canadian provinces, as well as in the Federal Court and the Supreme Court of Canada. We also participate regularly in hearings before a variety of provincial and federal tribunals, including: the Financial Services Tribunal, the Ontario Municipal Board, the Environmental Assessment Board, the Ontario Securities Commission, and the Autorité des Marchés Financiers (AMF).

In addition to our trial expertise, we assist clients in identifying and mitigating risks that could lead to new legal exposures. We focus on developing a deep knowledge of each client’s business, which enables us to intervene effectively to avoid lengthy proceedings or to achieve cost-effective and innovative solutions through early prevention or alternative dispute resolution. Our discovery management specialists work strategically with our litigators and clients to deliver an array of customized, cost-effective and efficient discovery solutions. In short, Osler is home to a critical mass of top litigators in their respective fields — with the track records and the loyal and growing client base to prove it.

Ask us about:

  • Appeals
  • Class Actions
  • Competition/Antitrust Litigation
  • Constitutional and Public Law
  • Construction and Infrastructure Litigation
  • Corporate Governance and Securities Litigation
  • Cross-Border Litigation
  • Defamation (Libel and Slander)
  • Discovery Management
  • Energy and Natural Resources Litigation
  • Environmental Litigation
  • Franchise Litigation
  • Insolvency and Restructuring
  • Intellectual Property Litigation
  • International Commercial Arbitration and ADR
  • Municipal Litigation
  • Pensions and Benefits Litigation
  • Product Liability
  • Professional Negligence
  • Tax Dispute Resolution


Sonia Bjorkquist

Partner, National Chair, Litigation


Mary Buttery, KC

Partner, Litigation


Maureen Killoran, KC

National Co-Chair

Calgary, Vancouver

Deborah Glendinning

Partner, Litigation


Éric Préfontaine

Partner, Litigation


  • Boart Longyear Company

    Boart Longyear in the sale of its shares to American Industrial Partners Capital Fund

  • Business Council of Alberta

    Significant decision at the Supreme Court of Canada: five judge majority finds the Impact Assessment Act unconstitutional

  • Nieuport Aviation Infrastructure Partners

    Nieuport Aviation in obtaining a judgment of over $130 million against Porter Airlines in the case of Porter Airlines Inc. v. Nieuport Aviation

  • TerraFarma

    TerraFarma in its up to $68 million acquisition by Aurora Cannabis

  • Toronto Transit Commission

    Toronto Transit Commission in connection with the Toronto-York Spadina Subway Extension

  • GitHub Inc.

    GitHub Inc. in its class proceeding concerning an alleged data breach involving the information of credit card applicants

  • City of Toronto

    City of Toronto in connection with Union Station Litigation

  • Veolia Health Operating Services

    Veolia Health Operating Services in the design-build defect claims against the constructors of the new Centre Hospitalier de l’Université de Montréal

  • Utilities Kingston

    Utilities Kingston in its $30 million construction litigation dispute with North America Construction

  • Trans Mountain Canada Inc.

    Trans Mountain Canada Inc. in its successful defence of four judicial review applications at the Federal Court of Appeal, challenging the June 2019 federal approval (Order in Council) of the Trans Mountain Pipeline Expansion Project

  • Trans Mountain Canada Inc.

    Supreme Court of Canada rules in favour of the Trans Mountain Expansion Project

  • National Tire Distributors

    National Tire Distributors in its road security rating re-evaluation before the Commission des transports du Québec

  • Kinder Morgan Canada Limited

    Kinder Morgan Canada Limited in its litigation victories for the Trans Mountain Pipeline Expansion

  • Terra Nova Consortium

    Terra Nova Consortium in a challenge over its calculation of past and ongoing provincial royalties

  • KRIM Biopharma Inc.

    KRIM Biopharma Inc., as well as its directors, with respect to the defence of a breach of contract and oppression claim brought by Stiefel Laboratories, Inc. in the Ontario Superior Court seeking $200 million in damages

  • Nobel Real Estate Investment Trust

    Nobel Real Estate Investment Trust in relation to its combination with Edgefront REIT

  • Jazz Aviation

    Successfully represented Jazz Aviation in a complex cost benchmarking arbitration against Air Canada.

  • Shell Canada Limited

    Shell Canada Limited before the Supreme Court of Canada in the successful defence of a Leave to Appeal application by Athabasca Chipewyan First Nation in the application regarding the Jackpine Mine Expansion Project.

  • Nalcor Energy

    Successfully represented Nalcor Energy before the Federal Court of Canada in a judicial review in relation to a major hydro-electric project at Churchill Falls, Newfoundland and Labrador.

  • Shell Canada Limited

    Shell Canada Limited in the successful defence of a Leave to Appeal and Stay Application before the Alberta Court of Appeal in re: Métis Nation of Alberta Region 1 v Joint Review Panel, 2012 ABCA 352

  • Amex Bank of Canada

    Amex Bank of Canada in two class action merits trials before the Québec Superior Court involving foreign exchange conversion fees on credit cards, and claiming over $650 million in damages.

  • Beaverbrook Art Gallery

    The Beaverbrook Art Gallery in a successful public arbitration and appeal brought by the Beaverbrook Foundation of the United Kingdom in a dispute over some 130 works of art valued at over $100 million.

  • CanWest and The National Post Company

    CanWest and The National Post Company in successfully obtaining summary judgment for $22.5 million plus compound interest against Hollinger International arising from an agreement by which an affiliate of CanWest purchased the remaining 50% interest of Hollinger International and its affiliates in The National Post Company.

  • Dell Canada Inc.

    Dell Canada Inc. in a successful appeal before the Supreme Court of Canada in a matter concerning the ability of companies to oust the provincial class actions regime in favour of a contractual arbitration.  

  • GE Capital Canada

    GE Capital Canada in a successful appeal to the Tax Court of Canada regarding an income tax assessment that denied its deduction of guarantee fees paid to its U.S. Parent. This is a major decision in the growing area of transfer pricing litigation.

  • Find More

  • Chambers Canada: Canada’s Leading Lawyers for Business: Recognized in Litigation: General Commercial (Nationwide; Ontario; Alberta; Quebec)
    • "The firm is very professional and very highly regarded."
    • "They really understand the business and they are extremely responsive. They don't try and over-lawyer files and their answers are always practical."
    • "They have good bench strength and have really taken the time to learn our business. They are bright, hard-working individuals."
    • "They are excellent and I have really enjoyed working with them. They have some really great young talent."
    • "They are really strong counsel, and frequently appear on top cases."
  • The Canadian Legal Lexpert Directory: Recognized in Corporate Commercial Litigation (Toronto, Ontario;  Montréal, Québec; Calgary, Alberta); Professional Liability (Toronto, Ontario)
  • Legal 500: Recognized in Dispute Resolution (Alberta; Ontario; Québec)
  • Benchmark Litigation Canada: Recognized in Dispute Resolution (Ontario, Québec, Alberta); Osler lawyers recognized in Litigation and Dispute Resolution
  • Best Lawyers Canada: Recognized as "Law Firm of the Year" in the area of Corporate and Commercial Litigation (Canada), 2022