Peter Griffin


Peter* is not a stranger to being in charge. In fact, he's known for it. Whatever side you are on, he is acclaimed for his tough but fair approach to his cases. Recognized as one of Canada's 25 Most Influential Lawyers, Peter commands§ respect from judges and opposing counsel for his fearless advocacy and extraordinary judgment. Peter tackles the most challenging commercial matters with expertise, because, after 35 years, he has the experience to skillfully guide his clients to success. Peter has a way of controlling the room from the boardroom up to the Supreme Court of Canada. He is a past President of The Advocates' Society and Fellow and former Chair of the American College of Trial Lawyers Ontario Committee. .



Peter Griffin

is one of the five founding partners at Lenczner Slaght.

"One of the top lawyers in Toronto, if not the top – he's a tough, aggressive but fair and smart commercial litigator who you can rely on, as he has fantastic judgment." — Chambers Global

Peter is recognized by his peers as one of the top litigators in Canada, particularly in the areas of corporate commercial litigation, class actions, securities matters, insolvency, and professional and director/officer liability. He has appeared before all levels of court in Ontario and the common-law provinces, and before the Supreme Court of Canada. Peter has been recognized by Canadian Lawyer as one of Canada's 25 Most Influential Lawyers and named "Lawyer of the Year" by Best Lawyers for his leadership in Corporate and Commercial Litigation (2017, Toronto).

Peter has extensive experience in complex cross-border litigation, especially as it relates to both class proceedings and insolvency and restructuring. He regularly advises boards of directors and national and multinational corporations with respect to their obligations.  He is retained as counsel of choice on appeal. He frequently represents clients in arbitration and acts as an arbitrator in contested arbitration proceedings. Peter is constantly sought out as an expert speaker on advocacy, shareholder disputes, class actions, professional liability and insolvency and restructuring.

Peter is past President of The Advocates' Society, a Fellow of the American College of Trial Lawyers and past Chair of the American College of Trial Lawyers Ontario Committee.

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  • American College of Trial Lawyers - Fellow; Chair, Ontario Committee

  • The Advocates' Society - Past President 2012–2013

  • Canadian Bar Association

  • Ontario Bar Association

  • Sir William Campbell Foundation

  • Commercial List Users' Committee

  • Turnaround Management Association

  • Fixing the Mistake: Limitation Periods in Professional Negligence Cases

    Over a decade after Ontario’s Limitations Act, 2002 came into force, courts are still grappling with when a cause of action is discoverable and a limitation period starts to run.  An increasingly litigated question relates to whether a limitation period runs while efforts are ongoing to fix the error that gave rise to the plaintiff’s claim. The Court of Appeal for Ontario recently addressed this issue in Presidential MSH Corp v Marr, Foster & Co LLP.

    Peter Griffin | June 20, 2017

  • In contractual disputes, after-the-fact conduct is admissible after all

    To most people, a contract is a written agreement, typically signed by all parties, that sets out what different parties promise to do.  But what happens that the written agreement is ambiguous?  Courts have long held that evidence of the “factual matrix” of the contract—that is, the surrounding circumstances that inform the context in which a contract is created—is admissible in the interpretation of a contract.  In its recent decision in Shewchuk v Blackmont Capital Inc, the Ontario Court of Appeal confirmed that evidence of subsequent conduct may also be admissible to interpret the agreement itself.

    Peter Griffin & Paul-Erik Veel | December 8, 2016

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  • American College of Trial Lawyers (2004)


  • Benchmark Canada (2012-2019)

    Top 50 Trial Lawyer in Canada and Litigation Star - Competition, General Commercial, Insolvency, Professional Liability and Securities

  • Best Lawyers (2006-2019)

    Appellate Practice, Bet-the-Company Litigation, Class Action Litigation, Corporate & Commercial Litigation, Director & Officer Liability, Health Care Law, Insolvency & Financial Restructuring, Legal Malpractice, Securities

  • Best Lawyers (2013)

    Toronto Corporate and Commercial Litigation "Lawyer of the Year"

  • Best Lawyers (2014)

    Toronto Bet-the-Company Litigation "Lawyer of the Year"

  • Best Lawyers (2016)

    Toronto "Lawyer of the Year" in Director and Officer Liability

  • Best Lawyers (2017)

    Toronto "Lawyer of the Year" in Corporate and Commercial Litigation

  • Best Lawyers (2019)

    Toronto "Lawyer of the Year" in Legal Malpractice Law

  • Canadian Lawyer (2014)

    Top 25 Most Influential Lawyers - Corporate Commercial Law

  • Canadian Legal Lexpert® Directory (2012-2019)

    Class Actions, Insolvency & Financial Restructuring, Litigation - Corporate Commercial, Litigation - Directors' & Officers' Liability, Litigation - Securities, Medical Negligence, Professional Liability

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