Expertise
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Practice Areas:
- Bar Admissions:
- Education:
- Queen's University (1977) LLB
- Carleton University (1974) BA
Details
- Bio
- Cases
- Associations
- Blog Posts
- News & Media
- Publications & Presentations
- Recognition
Peter Griffin , K.C., LSM, ASM
is counsel and one of the five founding partners at Lenczner Slaght.
"Peter Griffin is one of the best litigation lawyers in Canada. He has an excellent grasp of the issues and the law, as well as the gravitas to address difficult issues." — Chambers Canada
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.
In 2021, Peter received the prestigious Law Society Medal in recognition of his exceptional advocacy, unwavering commitment to education and mentorship, and involvement in positively advancing the legal profession. In 2024, Peter was awarded The Advocates' Society Medal, the Society's highest honour, celebrating his pre-eminence in advocacy, exemplary leadership, and significant contributions to the profession of law as well as the community at large.
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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WSIB Investments (Infrastructure) Pooled Fund Trust et al v Plenary Group (Canada) Ltd. et al
Successful trial counsel to two employee pension and injured workers funds in a breach of fiduciary duty and breach of contract claim with a manager of public infrastructure projects.
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Counsel to the Attorney General of Ontario in an appeal regarding the constitutionality of legislation that capped public sector compensation increases. A decision which interprets the scope of the right to freedom of association under section 2(d) of the Charter.
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Counsel to the former CFO of a TSX listed financial corporation in relation to a CPAO disciplinary proceeding.
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Waldron v His Majesty the King in Right of Canada et al
Counsel to the Claims Administrator in a motion and appeal arising from a dispute over the interpretation of the Indian Day School Settlement Agreement.
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Boyer v Callidus Capital Corporation
Counsel to a former employee at Callidus Capital Corporation, who commenced a wrongful dismissal claim in 2017. Callidus counterclaimed against our client for $150 million, which we successfully argued to have dismissed as an “Anti-SLAPP” proceeding at the Court of Appeal. We then obtained summary judgment in the main employment action for over $1.3 million plus interest.
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Annapolis Group v Halifax Regional Municipality
Counsel to the plaintiff in an action concerning alleged de facto expropriation, misfeasance in public office, and unjust enrichment relating to the plaintiff’s efforts to develop its lands within the Halifax Regional Municipality. Successfully represented the plaintiff at the Supreme Court of Canada with the Court clarifying the test for de facto expropriation and concluding that our client’s claim for de facto expropriation could proceed to trial.
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Internal investigation into allegations of breaches of confidentiality in a publicly-traded corporation.
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Grant Thornton v New Brunswick
Counsel to Grant Thornton in a successful appeal to the Supreme Court of Canada clarifying the rule of discoverability in limitation periods law across Canada.
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Counsel to the successful partner of a multi-billion dollar residential and commercial real estate developer and builder in obtaining successful order winding up and selling the partnership.
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Cameron Stephens Mortgage Capital Ltd v 1091369 Ontario Inc
Counsel to a construction lender in an application to appoint a receiver.
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American College of Trial Lawyers - Fellow; Chair, Ontario Committee
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The Advocates' Society - Past President 2012–2013
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Canadian Bar Association
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Ontario Bar Association
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Sir William Campbell Foundation
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Commercial List Users' Committee
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Turnaround Management Association
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Quadrennial Commission for Judicial Compensation - Commissioner (2016-2023)
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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.
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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.
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Lenczner Slaght’s Trial Lawyers Successful in $259 Million Judgment for Public Sector Funds
In WSIB Investments (Infrastructure) Pooled Fund Trust v Plenary Group (Canada) Ltd, our expert litigators were successful in obtaining a $259 million judgment in disgorgement for our clients, two employee pension and injured workers funds, against the Defendants for breach of fiduciary duty, knowing assistance, and knowing receipt. The 7-week trial before the Manitoba Court of King’s Bench was the first fully electronic trial to be completed in the province.
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Lenczner Slaght Lawyers Recognized as Canada’s Leading Litigators
Following an in-depth peer review process across the legal profession, 21 Lenczner Slaght lawyers have been recognized in the 2024 Lexpert Special Edition: Canada’s Leading Litigation Lawyers guide for their extensive courtroom experience and subject-matter expertise.
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Lenczner Slaght Recognized as a Leading Litigation Firm in Legal 500 Canada
Canada’s leading litigation firm has reaffirmed its Tier 1 ranking in Dispute Resolution in Legal 500 Canada.
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Chambers Canada Recognizes Lenczner Slaght’s Deep Bench of Expert Litigators
Canada’s leading litigation firm continues to advance their position in the latest edition of the world-renowned directory.
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Lenczner Slaght Litigators Recognized as the Best Lawyers in Canada
In the 2025 edition of Best Lawyers in Canada, Lenczner Slaght is proud to receive 168 total rankings, with 45 of our expert litigators recognized for their expertise across 25 practice areas.
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The 2024 Lexpert Directory Recognizes Lenczner Slaght’s Litigation Excellence
Lenczner Slaght’s litigators continue to be recognized by their peers as the foremost practitioners in their fields.
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Peter Griffin Awarded The Advocates’ Society Medal
Lenczner Slaght is proud to announce that Peter Griffin will be the 2024 recipient of The Advocates’ Society Medal, to be presented at a special awards ceremony in the Fall of 2024.
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Chambers Global Recognizes Lenczner Slaght for the 22nd Consecutive Year
Canada’s leading litigation firm and its expert litigators are increasingly recognized in the latest edition of world-renowned directory, Chambers Global.
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Lenczner Slaght Remains at the Centre of the Lexpert Bull’s Eye
The 2024 Lexpert®/American Lawyer Guide to the Leading 500 Lawyers in Canada recognizes Lenczner Slaght as the #1 firm in Toronto for Litigation and Commercial Litigation for the 23rd consecutive year.
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Lexpert Recognizes Lenczner Slaght’s Litigation Strength
An increasing number of our expert litigators continue to be recognized as the foremost lawyers in their fields by peers and senior members of the legal profession.
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2023 Securities Litigation Conference
Peter Griffin was invited to share his expertise on the panel Significant Recent Civil Securities Litigation Decisions.
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Peter Griffin was invited to the Queen's Law Litigation Society's Industry Night. Peter spoke about his litigation practice, the future of the practice, and more.
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Peter Griffin co-chaired The Advocates' Society program "Litigating Contract Disputes". Peter led the panels Drafting Effective Pleadings in Contract Disputes and View from the Bench: Litigating Contract Disputes.
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Peter Griffin presented at The Advocates' Society's program "Litigating Contract Disputes". He will share his expertise on the panel Framing Your Contract Claim.
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Peter Griffin and Tom Curry spoke at The Advocates' Society's 19th Annual Spring Symposium on the module The Civil Advocate. Their session included an update on principles of civility for advocates and how to handle questions from the Bench on appeal.
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Professionalism and Civility at Trial
Peter Griffin presented at the Ontario Bar Association's premier program Anatomy of a Trial: A Deeper Dive Into Jury Trials that provided a comprehensive examination of the best techniques for conducting a jury trial. Peter spoke on the panel "Professionalism and Civility at Trial".
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35th Annual Joint Colloquium on International Arbitration
Ian Binnie and Peter Griffin presented at the 35th Annual Joint Colloquium on International Arbitration. They shared their expertise on the panel discussion Mastering Effective Techniques for Cross-Examination.
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Peter Griffin spoke at The Advocates' Society's program on "Litigating Contract Disputes". He was a member of the "Framing Your Contract Claim" panel.
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15th Annual Symposium on Class Actions
As one of the leading experts in Class Actions, Peter Griffin spoke at Osgoode PD's 15th Annual Symposium on Class Actions on the panel "What Goes Around Comes Around: Lawyers Under Class Action Attack".
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Peter Griffin presented at the Advocates' Society's program on Motions Advocacy. He shared his expertise and experience on how to prepare oral and written submissions.
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The Advocates' Society Medal (2024)
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Law Society Medal (2021)
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Ontario Bar Association Award for Excellence in Civil Litigation (2017)
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American College of Trial Lawyers (2004)
Fellow
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Benchmark Canada (2012-2024)
Top 50 Trial Lawyer in Canada & Litigation Star – Commercial, Competition, Insolvency, Professional Liability, Securities
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Best Lawyers in Canada (2006-2025)
Alternative Dispute Resolution, Appellate Practice, Bet-the-Company Litigation, Class Action Litigation, Corporate & Commercial Litigation, Director & Officer Liability, Health Care Law, Insolvency & Financial Restructuring, Legal Malpractice, Medical Negligence, Securities
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Best Lawyers in Canada (2013)
Toronto Corporate and Commercial Litigation "Lawyer of the Year"
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Best Lawyers in Canada (2014)
Toronto Bet-the-Company Litigation "Lawyer of the Year"
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Best Lawyers in Canada (2016)
Toronto "Lawyer of the Year" in Director and Officer Liability
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Best Lawyers in Canada (2017)
Toronto "Lawyer of the Year" in Corporate and Commercial Litigation
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