Expertise
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Practice Areas:
- Bar Admissions:
- Education:
- LawVision Group (2017) Legal Project Management
- Queen's University (2012) JD (Dean's Honours List)
- University of Toronto (2008) HBA (Criminology, Sociology and Philosophy – High Distinction)
Details
- Bio
- Cases
- Associations
- Blog Posts
- News & Media
- Publications & Presentations
- Recognition
Jonathan Chen (he/him)
is a partner at Lenczner Slaght.
"Jonathan is a leader in the industry. He's bright, thoughtful, thorough, and open in his thinking." — Chambers Canada
Jonathan’s litigation practice is focused on class actions, business disputes, product liability and professional negligence matters. His clients have included financial institutions, technology companies, real estate developers and pharmaceutical companies. He has appeared before the Ontario Superior Court of Justice, the Ontario Court of Justice, the Ontario Court of Appeal, the Federal Court as well as administrative tribunals.
Prior to joining the firm, Jonathan articled and practiced at a leading national law firm where he defended banks, automotive companies, insurers, municipalities, police services boards and educational institutions. He also assisted on various class actions and was counsel on one of the first aggregate damages decisions in Canada.
While at law school, Jonathan was a Co-Editor-in-Chief of the Queen's Law Journal and a Teaching Assistant in Legal Writing and Research.
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Bell Media Inc et al v Warner Bros. Discovery et al
Counsel to the Warner Bros. Discovery entities responding to Bell Media Inc.’s request for a permanent injunction seeking to prevent Warner Bros. Discovery from licensing television content to Rogers Communications Inc.
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Larsen v ZF TRW Automotive Holdings Corp; Roy v TRW Automotive
Counsel to an automotive parts manufacturer in proposed class actions in British Columbia and Ontario relating to allegedly defective airbag control units. Successful in having certification dismissed.
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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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Counsel to the defendants in a class action alleging failure to disclose foreign exchange fees in registered accounts.
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Flette v The Government of Manitoba
Counsel to class counsel in obtaining legal fees of $25 million in a class proceeding arising from the handling of the Children's Special Allowance (CSA) program by the Government of Manitoba.
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Bernstein v Peoples Trust Company
Counsel to the Defendants in a class proceeding alleging that various brands of network-branded payment cards were subject to activation, dormancy, and other fees that constitute misrepresentations, breach of contract, and breaches of various provincial consumer protection legislation and related regulations.
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Lacroix v Walmart Canada Corporation; Dussiaume v Walmart Canada Corporation
Counsel to Walmart in proposed class actions in Ontario and British Columbia relating to the manufacturing, supply and sale of Zantac Ranitidine. Successfully in having action dismissed.
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Ramdath v George Brown College of Applied Arts and Technology
Counsel to the defendant at trial and appeal in a consumer protection class action brought by former students. (Prior to joining Lenczner Slaght)
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Counsel to General Motors in defence of class actions relating to defective ignition switches and airbags. (Prior to joining Lenczner Slaght)
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City of Hamilton Judicial Inquiry
Counsel to the City of Hamilton in a Judicial Inquiry into the Red Hill Valley Parkway.
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Canadian Bar Association
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Ontario Bar Association - Technology Liaison, Civil Litigation Executive (2025-2026); Member-at-Large, Class Actions Executive (2019-2021; 2024-2026)
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The Advocates' Society
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Pro Bono Law Ontario - Duty Counsel
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University of Toronto - New College Career Mentorship Program
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Federation of Asian Canadian Lawyers
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The Ontario Court of Appeal’s decision in Price v Smith & Wesson Corporation is a significant development in product liability law and class action procedure, particularly in cases involving harm from criminal acts. The ruling allows a class action in negligence to proceed against Smith & Wesson, the manufacturer of the handgun used in the 2018 Danforth Avenue mass shooting in Toronto.
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In North v Bayerische Motoren Werke AG, the Ontario Court of Appeal delivered a significant ruling on the boundaries of product liability in negligence. The decision confirms that negligence claims for pure economic loss in product liability cases can only succeed in narrow circumstances. For class action and product liability lawyers, the case serves as a reminder of the limits that govern certification in negligence-based claims.
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Canada’s federal structure means national class actions naturally raise potential constitutional questions. Those questions become potentially more thorny where a class action is pursued not on behalf of individuals across multiple provinces and territories, but instead provincial and territorial governments themselves. The Supreme Court’s recent decision in Sanis Health Inc v British Columbia addressed many of those concerns and ultimately defined a broad scope for national class proceedings, including where a proposed class includes other provincial or territorial governments.
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AI Competence in the Courtroom: Four Things Judges Need to Understand Now About AI
As artificial intelligence continues to permeate every aspect of our lives, legal challenges involving AI will proliferate. Parts 1 to 3 in our series explored many of these potential questions. AI will create new legal problems and change the texture of old ones. As always, the judiciary, with the assistance of counsel, will assume a pivotal role in navigating this landscape.
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Pay to Play: Court of Appeal Enforces Full Payment of Lender Fee
Barring a very narrow set of circumstances, sophisticated parties with equal bargaining power are generally held to the terms of their agreement. 660 Sunningdale GP Inc v First Source Mortgage Corporation is a recent example where a commercial developer, 660 Sunningdale GP, was ordered to pay the entirety of the lender fee to the lender, First Source Mortgage Corporation, even though the loan did not proceed.
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No Harm, No Remedy: The Availability of Non-Compensatory Remedies under the Consumer Protection Act
By playing their essential gatekeeping role, class action judges have in numerous decisions clarified the necessary elements of various causes of action and the availability of specific remedies in a particular case. What constitutes harm that is compensable, for example, has featured in numerous product liability class actions and the failure to show harm has put an end to many of them. For strategic and practical reasons, some class actions do not seek compensation for losses that the class members suffered. Instead, the strategy is to pursue remedies that do not correspond with personal losses such as disgorgement, nominal damages and punitive damages. Hoy v Expedia Group Inc is a recent example.
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Court Affirms Extreme Circumstances Required to Restrain Power of Sale
A power of sale is a very common mortgage remedy used by lenders where a borrower defaults under the applicable mortgage agreement. In light of the current interest rate environment, the power of sale process has anecdotally been exercised more frequently. Lenders (and borrowers), however, should keep in mind when such a right can be restrained.
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Pleadings continue to be a popular battleground in the product liability context. Over the years, a body of law has developed respecting motions to strike for negligent design, negligent manufacture and failure to warn claims. Nevertheless, there continues to be debate as to the specificity needed for pleading these types of claims. That debate is fuelled in part by jurisprudence demonstrating a high tolerance for claims that are arguably vague and lacking in material facts. Even where a claim is struck, plaintiffs are routinely permitted to amend their pleading.
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A few years after the Supreme Court of Canada released Hollick v Toronto (City), which provided a detailed articulation of the common issues requirement under s. 5(1)(c) of the Class Proceedings Act, 1992, Ciara released her chart-topping single, “1, 2 Step”. While we would not go so far as to say that her single was one of the most succinct summaries of the common issues test from the early 2000s, she may have been on to something.
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Recall Remedy Once Again Preferable to Class Action
History has shown that recalls for product defects are often followed by a proposed class action lawsuit. While many products cases in that context have been certified, we have now seen certification of proposed class actions being denied on the basis that there is already an effective recall campaign in place. We have seen this in Maginnis and Magnaye v FCA Canada et al and Richardson v Samsung.
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2025 Lexpert Directory Highlights Lenczner Slaght’s Excellence in Advocacy
Peers and senior members of the legal profession across the country continue to recognize the depth and breadth of Canada’s leading litigation firm in the latest 2025 Canadian Legal Lexpert Directory.
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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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Jonathan Chen Named a 2024 Lexpert Rising Star
For his exceptional advocacy, commitment to advancing EDI and innovation, and dedication to mentorship, Jonathan Chen was recognized as a 2024 Lexpert Rising Star at last night’s award ceremony at the Liberty Grand in Toronto.
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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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Jonathan Chen Named FACL’s Mentor of the Year
Jonathan Chen was recognized at the 17th Annual FACL Gala on Saturday, March 2 for his demonstrated positive impact on the professional development and career trajectory of members of the legal community, and particularly the Asian community, through mentorship.
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New College Arbor Award Winners 2023
Jonathan Chen was honored with a 2023 Arbor Award, in recognition of his outstanding and enduring contributions to the University of Toronto. Following his extraordinary experience in the New College Career Mentorship Program, Jonathan returned to volunteer his time with the program as a mentor. In this capacity, Jonathan helps students learn more about the application process, navigating law school, and working as a lawyer.
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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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Lenczner Slaght Litigators Recognized as Best Lawyers in Canada
In the latest edition of Best Lawyers in Canada, 41 of our expert litigators are recognized for their expertise across 24 practice areas. The following lawyers have also been recognized as “Lawyer of the Year” for receiving the highest overall peer-feedback in their practice areas in Toronto.
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Lenczner Slaght’s Litigation Excellence Recognized in 2023 Lexpert Directory
Following comprehensive peer review surveys and interviews with senior members in the legal profession, the 2023 Canadian Legal Lexpert Directory has recognized 31 of the firm’s expert litigators for their experience, knowledge, and precision, with 108 rankings spanning 17 practice areas.
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46th Annual Intensive Trial Advocacy Workshop (ITAW)
Lawrence Thacker, Risa Kirshblum, Monique Jilesen, Brendan Morrison, and Jonathan Chen will participate as instructors at the 46th Annual Intensive Trial Advocacy Workshop (ITAW), hosted by Osgoode Professional Development. Jonathan McDaniel and Kate Costin will also take part in ITAW, serving as Mock Expert Witnesses. This program will gather over 100 experts in advocacy skills training and guest speakers who are active members of the Bench and Bar. Attendees will have the opportunity to develop and refine their advocacy skills.
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Your Essential Evidence Refresher
Jonathan Chen was invited to share his expertise at the Ontario Bar Association program, Your Essential Evidence Refresher. Jonathan provided expert insights on key principles such as admissibility, important evidentiary rules, and recent developments.
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2024 Class Actions Wrap-Up: Top 10 Cases Across Canada
2024 was another noteworthy year for class actions in Ontario and across the country. In our Class Actions Wrap-Up, Paul-Erik Veel, Jonathan Chen, and Arash Nayerahmadi highlight our top 10 class action decisions of 2024. These decisions reflect the most significant developments of the last year, and we expect they will set the tone for 2025.
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Lynne McArdle and Jonathan Chen co-authored the article Assessment of Parallel Class Proceedings in Multiple Provinces Should Occur at Certification and Not on Preliminary Stay Motion, published on the Ontario Bar Association’s Class Actions Law Section. In this article, Lynne and Jonathan discuss the BC Court of Appeal’s decision in InvestorCOM Inc v L’Anton, which confirms that parallel class actions are not an abuse of process and that staying such actions before certification requires extraordinary circumstances.
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2024 Snapshot: Through the Lens of Lenczner Slaght
Lenczner Slaght launches our 2024 Snapshot, which highlights the most significant developments, decisions, and trends in litigation from the past year across 20 areas of expertise. Reflect on 2024 and look ahead to 2025 through the lens of our expert litigators.
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Artificial Intelligence for Litigators: More AI in Action!
Jonathan Chen was invited to share his expertise at The Advocates’ Society’s program on Artificial Intelligence for Litigators: More AI in Action! This program demonstrated concrete examples of how AI can assist with daily advocacy tasks. Jonathan spoke on the topic, “Alexi in Action”.
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AI Applications: Business of Law & Practical Use Cases
Jonathan Chen was invited to speak at Colloquium Sudbury 2024 as part of the AI Plenary. He shared his expert insights on the panel AI Applications: Business of Law & Practical Use Cases.
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Jonathan Chen, Mahgol Taghivand, and Catherine Blair participated in Connect for Success, an annual event hosted by Queen’s Law to support second-year students with their preparation for the Toronto summer student recruitment process. In addition to attending, Mahgol spoke on a panel where she shared her experience and discussed various aspects related to student recruitment.
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45th Annual Intensive Trial Advocacy Workshop (ITAW)
Risa Kirshblum, Sana Halwani, and Jonathan Chen participated as instructors at the 45th Annual Intensive Trial Advocacy Workshop (ITAW), hosted by Osgoode Professional Development. This program gathered over 100 experts in advocacy skills training and guest speakers who are active members of the Bench and Bar. Attendees had the opportunity to develop and refine their advocacy skills.
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No Harm, No Remedy: Limiting Principles Under the Ontario Consumer Protection Act
Jonathan Chen and Christine Windsor co-authored the article "No Harm, No Remedy: Limiting Principles Under the Ontario Consumer Protection Act", published in Class Action Defence Quarterly. In this article, Jonathan and Christine discuss Hoy v Expedia Group Inc, analyzing the limitations for class proceedings under the Consumer Protection Act for consumers seeking damages without providing proof of individual loss. They emphasize that consumer protection legislation is not a vehicle for seeking remedies that overcompensate claimants.
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Lexpert Rising Stars (2024)
Leading Lawyers Under 40
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Canadian Legal Lexpert® Directory (2022-2025)
Class Actions, Litigation - Corporate Commercial, Litigation - Product Liability
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Best Lawyers in Canada (2022-2025)
Class Action Litigation, Corporate & Commercial Litigation
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Lexpert Special Edition: Canada's Leading Litigation Lawyers (2023-2024)
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Lexpert Special Edition: Canada's Leading Technology & Health Sciences Lawyers (2024)
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Mentor of the Year (2024)
Federation of Asian Canadian Lawyers
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Arbor Award (2023)
University of Toronto
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David Sabbath Prize in Labour Law: Collective Agreements and Arbitration (2012)
Queen's University, Faculty of Law
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Lexpert Special Edition: Canada's Leading Technology Lawyers (2025)