Expertise
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Practice Areas:
- Bar Admissions:
- Education:
- Osgoode Hall Law School (1998) LLB
- Queen's University (1995) BA (Honours - Political Science)
- LawVision Group (2015) Legal Project Management
Details
- Bio
- Cases
- Associations
- Blog Posts
- News & Media
- Publications & Presentations
- Recognition
Monique Jilesen (she/her)
is Managing Partner at Lenczner Slaght.
"Monique is very client-focused, personable and strategic." — Chambers Canada
Monique is one of Canada’s leading litigators who clients turn to for their toughest commercial disputes. Her practice focuses on class actions, contract and shareholder disputes, civil fraud, injunctions, professional liability, bankruptcy and insolvency matters, and securities cases.
A fearless advocate, Monique is unafraid to take on tough, notable, and high-profile cases, even at a moment’s notice. She was counsel to the Ukrainian World Congress in an application for judicial review of Canada's decision to allow the delivery of turbines to Germany for use by a sanctioned Russian company. In Li v Barber, she successfully secured an unprecedented Mareva order freezing up to $20 million of assets and cryptocurrency of Freedom Convoy leaders. She also represented Douglas Cardinal in an injunction to restrain the use in Canada of the Cleveland baseball team’s racist name and logo on human rights grounds.
Monique’s exceptional advocacy is widely recognized. Her accolades include The Advocates’ Society’s prestigious Douglas K. Laidlaw Award for Excellence in Advocacy, the 2023 Litigator of the Year honour at the Canadian Law Awards, and recognition as one of the Top 50 Most Influential by Toronto Life. She is also a Fellow of the American College of Trial Lawyers and the International Academy of Trial Lawyers.
She co-leads the firm’s Commercial Litigation practice group and serves as a member of the Commercial List Users’ Committee. In 2018, she developed commerciallist.com, an award-winning website that serves as a one-stop shop for all things Commercial List. As the firm's Managing Partner, Monique is at the forefront of executing the firm’s strategy, building an innovative mindset across the firm, and nurturing its high-performing and inclusive culture.
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Canadian News Media Companies v OpenAI (Jurisdiction Motion)
Counsel to Canada's leading news media organizations in successfully defending against a jurisdiction motion brought by OpenAI in this complex commercial and intellectual property litigation, which sought to stay or dismiss claims of copyright infringement breach of contract and unjust enrichment on the basis that the Ontario court lacked jurisdiction. The Ontario Superior Court of Justice (Commercial List) confirmed jurisdiction over OpenAI Inc. and related entities in this AI and technology dispute, allowing our clients' claims to proceed. Read the decision here.
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Counsel for the Respondent in successfully defending a complex cross-border foreign judgment enforcement application arising from long standing, multi-jurisdictional disputes. Successfully resisted the Ontario recognition and enforcement of a number of foreign judgments obtained against the Respondent in Ukrainian and British Virgin Islands.
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Lundin Mining Corporation v Dov Markowich
Counsel to the intervenor, CFA Societies Canada, at the Supreme Court of Canada in a matter that considers the definition of “material change” under the Securities Act.
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Counsel to Ernst & Young, as insolvency trustee of Quadriga Fintech Solutions Corp, in receivership proceedings involving fraud litigation.
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Chartered Professional Accountants of Ontario Proceeding
Counsel to the former Chief Commercial Officer of a reporting issuer in the federally regulated cannabis industry defending a professional discipline proceeding before the Discipline Committee of the Chartered Professional Accountants of Ontario (CPA Ontario).
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Global Food and Ingredients Inc v Marina Commodities Inc
Counsel to the Court-appointed Receiver for Global Food and Ingredients Inc. in bringing litigation and arbitration against a customer arising from unpaid invoices in the food industry.
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VIA Rail Canada Inc v Canadian National Railway Company and Attorney General of Canada
Counsel to Canadian National Railway Company in successfully responding to a judicial review brought by VIA Rail Canada Inc. in the Federal Court of Canada. Successfully brought a motion to strike the judicial review without leave to amend on the basis that CN is not a judicially reviewable decision-maker and the Federal Court did not have jurisdiction over the dispute.
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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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Canadian News Media Companies v OpenAI
Counsel to Canada’s leading news media organizations in bringing legal action against OpenAI for breach of copyright, breach of online terms of use, breach of contract, and unjust enrichment for scraping large swaths of content (millions of works) from Canadian media to help develop its artificial intelligence products, including ChatGPT.
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Bell Media Inc et al v Warner Bros. Discovery et al
Counsel to the Warner Bros. Discovery entities in 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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American College of Trial Lawyers - Fellow
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International Academy of Trial Lawyers - Fellow
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Commercial List Users’ Committee - Member
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International Bar Association
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The Advocates' Society - Treasurer, Board of Directors (2026-present); Secretary, Executive Committee (2025-2026); Board of Directors (2024-2025); Former Chair of the Commercial Litigation Practice Group (2018-2019)
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Canadian Bar Association
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Ontario Bar Association
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United Way Greater Toronto - Chair, 2024 Major Individual Giving Cabinet; Member, Women United
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Northwind Professional Institute - Steering Committee Member, Law Leaders Invitational Forum (2025-2026)
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International Women's Insolvency & Restructuring Confederation
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Women's White Collar Defense Association
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Turnaround Management Association
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Ontario Trial Lawyers Association Moot - Former Coach, Osgoode Hall Law School
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Osgoode Hall Law School - Former Adjunct Professor
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Gale Cup Moot Committee - Past Chair
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The Law Foundation of Ontario - Member, Class Proceedings Committee
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5-Year Retrospective: Injunctive Relief
The blog, 5-Year Retrospective: Injunctive Relief, co-authored by Monique Jilesen and Sahar Talebi was published on commerciallist.com as part of the Commercial List Year in Review: 5-Year Retrospective (2021-2025) guide. In this blog, they unpack the recent trends in Commercial List injunction jurisprudence, which demonstrate that the Court remains agile in applying injunctive remedies to address evolving commercial disputes, and that parties bringing an injunction in a commercial context should engage in a pragmatic analysis of their case, focusing on practical implications rather than getting caught up in technical classifications and labels.
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Pre-Construction Risk, Redefined: Ontario Courts Limit Developer Disclosure Obligations
In the Ontario Superior Court’s most recent decision affecting developers, De Bartolo v Icona Developments Inc, the Court held that neither the standard form agreements of purchase and sale nor the Condominium Act, 1998 obliged the developer of the Icona condominium project in Vaughan to disclose a restrictive covenant registered on title. Together with the Ontario Court of Appeal’s recent decision in Shiralian v Wyldewood Creek Inc, the ruling confirms that courts will give full effect to well-drafted contractual provisions that allocate risk in pre-construction transactions.
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On March 6, 2026, the Court of Appeal for Ontario released its decision in Shiralian v Wyldewood Creek Inc, dismissing the appellants' appeal and upholding the enforceability of a limitation of liability provision (also known as an exculpatory clause) contained in a pre-construction condominium purchase agreement. The decision is a welcome affirmation of the principles of freedom of contract and the enforceability of exculpatory clauses in the context of residential real estate development.
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Canadian Courts Have Jurisdiction to Address Misappropriation by AI Companies
In Toronto Star Newspapers Limited v OpenAI Inc, the Ontario Superior Court delivered a significant ruling on the jurisdiction of Ontario (and Canadian) courts to determine disputes relating to the misappropriation of content by artificial intelligence (AI) companies.
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Supreme Court: Public Disclosure Must Level the Playing Field Between Companies and Investors
In Lundin Mining Corp v Markowich, the Supreme Court of Canada delivered a significant ruling on the scope of disclosure standards for public companies in Canada, holding that disclosure standards should be interpreted broadly and flexibly to deter informational asymmetry between issuers and investors.
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The LCO’s Class Actions Final Report: The Defence Perspective
As has now been widely reported, the Law Commission of Ontario has released its final report on class actions which makes recommendations to improve the system of class actions in Ontario. Our colleagues, Brian Kolenda and Derek Knoke, commented on those that will be of interest to plaintiffs in their blog post here. We provide the defence counsel perspective here.
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The Rules of Evidence Still Apply in PMNOC Section 8 Cases
It’s no surprise to litigators that some courts tend to be relaxed with the rules of evidence in civil cases. In many contexts, courts are prepared to admit inadmissible hearsay evidence and simply address evidentiary concerns by noting that such evidence may be given less weight. That type of approach was often taken in cases under section 8 of the Patented Medicine (Notice of Compliance) Regulations.
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The weight of the corporate veil: It will be lifted with only the strongest tools
The "corporate veil" is an old and well-establish concept. Corporations are separate legal entities under the law and, generally, liability will not flow through the corporation and onto the owners and directors. This is why a corporate bankruptcy doesn't result in a flurry of debt collectors knocking on the door of every shareholder.
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Chambers Canada Highlights Lenczner Slaght as a Litigation Powerhouse
With 28 ranked lawyers and top-tier practice group rankings across 11 areas, Lenczner Slaght’s latest Chambers Canada results continue to reinforce that its reputation as Canada’s leading litigation firm is built on decades of courtroom excellence, national reach, and top-tier client service.
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49 Lenczner Slaght Litigators Named in Best Lawyers in Canada 2027
In the 2027 edition of Best Lawyers in Canada, 49 of our expert litigators earned 172 rankings across 26 practice areas, a testament to the depth and breadth of our advocacy.
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Google’s Bid to Buy Spirit Airlines’ Data Met With Pushback From Former Flight Attendants
Monique Jilesen was interviewed by Global News about the privacy risks in Google’s bid to purchase Spirit Airlines’ internal business data, including employee emails and Teams chats, to help train its AI models. She explains why a sale like this may not be approved in Canada unless the data is fully scrubbed of anything that could identify individual employees. Even then, she would expect a fight over approval.
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7 Lenczner Slaght Litigators Elected to Leadership Positions in The Advocates’ Society
As recognized leaders of the bar, our expert litigators will play an active role in advancing the mission of The Advocates' Society, helping to shape professional development through educational programs, networking events, volunteer initiatives, mentorship opportunities, and more.
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Lenczner Slaght Celebrates 25 Years on the Lexpert Bull’s-Eye
The 2026 Canadian Legal Lexpert Directory continues to recognize Lenczner Slaght as the #1 firm in Toronto for Litigation and Commercial Litigation.
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Lenczner Slaght Recognized in World-Renowned Directory, Chambers Global
For the 24th consecutive year, Canada’s leading litigation firm and its expert litigators have been recognized in world-renowned directory, Chambers Global.
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11 Lenczner Slaght Litigators Recognized in Lexpert 500 Cross Border
The 2026 edition of Lexpert's Leading 500 Cross-Border Lawyers features 11 of our preeminent lawyers, reflecting their exceptional advocacy and the trusted counsel they provide to clients navigating complex, high-stakes cross-border disputes.
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Lenczner Slaght Recognized in Legal 500 Canada for Litigation Excellence
As Canada’s leading litigation firm, we are proud to maintain our Tier 1 ranking in Dispute Resolution in Legal 500 Canada.
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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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Chambers Canada Highlights Lenczner Slaght’s Excellence in Advocacy
Canada’s leading litigation firm continues to be recognized in world-renowned directory, with new rankings highlighting its deep bench of expertise.
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Corporate Commercial Case Law Year in Review 2026
Monique Jilesen was invited to speak at the Law Society of Ontario’s Corporate Commercial Case Law Year in Review 2026 program, where she will present an update on good faith case law as part of a broader review of key business law decisions from the past year.
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International Bar Association's Annual Conference 2026
Monique Jilesen and Meghan Bridges will speak at the International Bar Association's Annual Conference.
Monique Jilesen will present on the panel titled, AI Disputes: What Are They, Where Do They Arise and What Challenges Do They Pose, discussing disputes arising from the development and integration of AI technology into other products and services, including issues of liability that may involve multiple parties across the AI supply chain. She will also address the advantages and limitations of arbitrating versus litigating these disputes.
Meghan Bridges will share her expertise on the session titled, Lions and Tigers and Bears, Oh My! Challenging Executive Decisions Made in Times of Emergency.
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47th Annual Intensive Trial Advocacy Workshop (ITAW)
Lawrence Thacker, Risa Kirshblum, Monique Jilesen, Sana Halwani, Brendan F. Morrison, and Jonathan Chen participated as instructors at the 47th 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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Commercial List Year in Review 5-Year Retrospective (2021-2025)
This guide offers data-driven analysis on all decisions published on CanLII from 2021-2025, an overview of the top 10 noteworthy cases, as well as key developments in insolvency matters, shareholder disputes, injunctions, and securities litigation.
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22nd Annual Class Actions Symposium 2026
Monique Jilesen was invited to share her expertise at OsgoodePD's Class Actions certificate program. In her session titled, Securities Class Actions, Monique discussed the current landscape of securities class actions in Canada, including key trends and emerging risks, recent case law, certification challenges unique to securities claims, and the role of expert evidence in damages modeling and market impact analysis.
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Women in Big Law: Leadership, Influence, and the Path Forward
Monique Jilesen was invited to share her expertise at the Ontario Bar Association’s Women Lawyers Forum Program. Monique discussed the meaningful advances the firm has made in recent years, the ongoing efforts to better support and elevate women in law, and the challenges and opportunities that remain. She also shared her experiences on building and sustaining a successful career and navigating complex leadership environments.
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An Updated Evidence Cheat Sheet
In the Spring 2026 issue of The Advocates' Journal, Monique Jilesen and Sam Hargreaves have updated Justice Perell's widely used Evidence Cheat Sheet, refreshing citations with more recent case law and sharpening its focus on civil litigation for use in trials, motions, and applications.
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Litigation as Business Strategy: Aligning Legal Action with Organizational Goals
Monique Jilesen was invited to share her expertise at the Canadian Bar Association program titled, Litigation as Business Strategy: Aligning Legal Action with Organizational Goals. Monique discussed ways to align litigation strategies with commercial outcomes and demonstrated how using data-driven tools can help shape smarter, more strategic decisions.
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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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Monique Jilesen was invited to share her expertise at the International Bar Association's Annual Conference in the session, Competing and Thriving: Can Small and Medium Size Law Firms Punch Above Their Weight Against International Legal Heavyweights? Monique discussed how small and mid-sized law firms can leverage collaboration, culture, networks, and technology to compete effectively with larger, global firms.
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Law Society Medal (2025)
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Toronto Life’s Top 50 Most Influential (2023)
Canada's Top Litigator
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Douglas K. Laidlaw Medal for Excellence in Advocacy (2017)
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Chambers Canada (2019-2027)
Litigation: General Commercial (Ontario)
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Canadian Legal Lexpert® Directory (2014-2026)
Class Actions, Insolvency & Financial Restructuring, Litigation - Corporate Commercial, Litigation - Directors' & Officers' Liability, Litigation - Securities
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Lexpert Guide to the Leading 500 Cross-Border Lawyers in Canada (2016-2026)
Corporate Commercial Litigation; Directors’ & Officers’ Liability Litigation (2025)
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Lexpert Special Edition: Canada's Leading Litigation Lawyers (2014-2025)
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Lexpert Guide to the Leading US/Canada Cross-Border Lawyers in Canada (2013-2019)
Dispute Resolution, Corporate Commercial Litigation, Litigation Lawyer to Watch (2013)
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Lexpert Special Edition: Canada's Leading Technology Lawyers (2021)
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Lexpert Zenith Award (2018)
Mid-Career Excellence in Corporate Commercial Litigation
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