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, complex commercial business disputes, injunctions, product liability and professional negligence matters. His experience includes representing clients in matters involving breach of contract claims, shareholder disputes, supply agreement disputes, fiduciary duty claims, consumer protection claims, receivership applications, as well as obtaining urgent injunctive relief. He was also counsel on one of the first class action aggregate damages decisions in Canada.
Jonathan has extensive trial and appellate experience. He has appeared before courts and tribunals across Canada, including the Ontario Superior Court of Justice (Commercial List), the Court of Appeal for Ontario, the Federal Court, and in British Columbia, Alberta, and Manitoba. His clients include financial services companies, accounting firms, real estate developers and lenders, pharmaceutical manufacturers, technology and media companies, consumer retailers, automotive manufacturers and dealers, transportation companies, insurers, municipalities, police services boards, and educational institutions.
Jonathan is also Chair of Lenczner Slaght's Innovation Hive and a key member of our AI Taskforce. A leading expert in integrating AI and technology into legal practice, he leads our efforts to streamline legal service delivery to ensure our lawyers can focus on where they add most value: in trial strategy, advocacy, and analysis.
Beyond the firm, Jonathan is a leading litigator in the Civil Litigation and Class Actions Bar. He serves as an elected member of the Ontario Bar Association’s Civil Litigation Executive and Class Actions Executive and is an active participant of the Federation of Asian Canadian Lawyers. He is frequently invited to speak as a recognized expert on topics such as trial advocacy, emerging class action and commercial litigation issues, the use of artificial intelligence in legal practice, and innovation.
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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’s application for a permanent injunction in a media licensing dispute involving television content rights and distribution to Rogers Communications Inc.
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Lacroix v Walmart Canada Corporation; Dussiaume v Walmart Canada Corporation
Counsel to Walmart in pharmaceutical product liability class actions in Ontario and British Columbia relating to the manufacturing, supply and sale of Zantac Ranitidine. Successful in having action dismissed.
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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. Successfully defeated class certification which took place in British Columbia.
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Bernstein v Peoples Trust Company
Counsel to a financial services company 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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Counsel to the defendant, a major financial institution, in a class action alleging failure to disclose foreign exchange fees in registered investment accounts
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Flette v The Government of Manitoba
Counsel to class counsel in securing $25 million in legal fees in an Indigenous rights class proceeding arising from the handling of the Children's Special Allowance (CSA) program by the Government of Manitoba.
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City of Hamilton Judicial Inquiry
Counsel to the City of Hamilton in a public inquiry into the Red Hill Valley Parkway, a significant municipal highway.
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Re: Ashcroft Urban Developments Inc
Counsel to a commercial lender in a contested CCAA Application concerning a real estate development with countervailing relief sought for the appointment of a receiver. Successfully obtained the appointment of a receiver over the debtor’s assets, and the debtor’s application for relief under the CCAA was denied.
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Frayce v BMO Investorline Inc; Michaud v BBS Securities Inc
Counsel to an investment dealer in proposed Ontario and British Columbia class proceedings relating to the receipt of trailing commissions by order-execution-only dealers. Successful in having certification motion dismissed.
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Rovi Guides and TiVo Solutions v Bell Canada
Counsel to TiVo Solutions and its subsidiary Rovi Guides in a patent infringement action, involving patents relating to interactive television program guides, DVR technology, and related technologies.
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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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Canadian Bar Association
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The Advocates' Society
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Federation of Asian Canadian Lawyers
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Ontario Trial Lawyers Association Moot - Coach for Queen’s Law Students
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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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Queen’s Law - Former Co-Editor-in-Chief of the Queen’s Law Journal; Former Teaching Assistant in Legal Writing and Research
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Court Says No to End Run: Hong Kong Arbitration Blocked in Binance Class Action
In cross-border litigation, the choice of venue is a major strategic consideration, and forum contests can be as hotly contested as the underlying dispute. In Lochan v Binance Holdings Limited, the Ontario Superior Court of Justice restrained Binance Holdings Limited (Binance) and an affiliated entity, Nest Services Limited (Nest), from pursuing an arbitration commenced in Hong Kong against the class representatives in a certified class action in Ontario. The decision shows how a parallel foreign arbitration raised the risk of a collateral attack on prior Ontario rulings, and why an anti-suit injunction was appropriate to preserve the integrity of the Ontario proceeding.
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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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Lenczner Slaght Recognized as Canada’s Leading Litigators
Based on an in-depth peer review process across the legal profession, 26 Lenczner Slaght lawyers are recognized in the 2025 Lexpert Special Edition: Canada’s Leading Litigation Lawyers for their exceptional advocacy and extensive courtroom experience.
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Lenczner Slaght Litigators Featured Among Best Lawyers in Canada
The 2026 edition of Best Lawyers in Canada recognizes Lenczner Slaght with 180+ rankings, featuring 48 of our expert litigators across 27 practice areas.
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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, Partner at Lenczner Slaght and a first-generation Asian-Canadian lawyer, 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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Jonathan Chen was invited to share his expertise at the Federation of Asian Canadian Lawyers’ 2026 Conference as a panelist on Law & Technology: Navigating AI, Innovation, and the Future of Practice. Jonathan will discuss the impact of AI on the legal practice, with a particular focus on litigation.
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2025 Snapshot: Through the Lens of Lenczner Slaght
We’ve released our 2025 Snapshot, highlighting the most significant developments, decisions, and trends in litigation from the past year across 21 practice areas. Reflect on 2025 and look ahead to 2026 through the lens of our expert litigators.
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17th Annual Class Actions Colloquium
Paul-Erik Veel and Jonathan Chen were invited to share their expertise at the OBA's 17th Annual Class Actions Colloquium. Paul-Erik and Jonathan discussed emerging issues in class actions law and practical tips for both plaintiff and defence counsel.
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Artificial Intelligence for Litigators: Next-Gen AI Tools in Action
Jonathan Chen was invited to share his expertise on the panel titled, Beyond Boolean: AI-Enhanced Research and Case Analysis on The Advocates' Society's program, Artificial Intelligence for Litigators: Next-Gen AI Tools in Action. Jonathan showcased Alexi, a legal AI platform, sharing how it’s evolved over the past year, its key use cases, and tips for getting the best results.
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46th Annual Intensive Trial Advocacy Workshop (ITAW)
Lawrence Thacker, Risa Kirshblum, Monique Jilesen, Brendan Morrison, and Jonathan Chen participated as instructors at the 46th Annual Intensive Trial Advocacy Workshop (ITAW), hosted by Osgoode Professional Development. Jonathan McDaniel and Kate Costin also took part in ITAW, serving as Mock Expert Witnesses. 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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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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Canadian Legal Lexpert® Directory (2022-2025)
Class Actions, Litigation - Corporate Commercial, Litigation - Product Liability
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Lexpert Special Edition: Canada's Leading Litigation Lawyers (2023-2025)
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Lexpert Special Edition: Canada's Leading Technology Lawyers (2025)
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Lexpert Special Edition: Canada's Leading Technology & Health Sciences Lawyers (2024)
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Best Lawyers in Canada (2022-2026)
Class Action Litigation, Corporate & Commercial Litigation
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Lexpert Rising Stars (2024)
Leading Lawyers Under 40
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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