Expertise
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Practice Areas:
- Bar Admissions:
- Education:
- University of Toronto (1986) LLB
- Queen's University BA (Political Studies)
Details
- Bio
- Cases
- Associations
- Blog Posts
- News & Media
- Publications & Presentations
- Recognition
William C. McDowell
is a partner at Lenczner Slaght and a Fellow of the American College of Trial Lawyers.
"William is an exceptional litigator and a great communicator. His work is of the highest calibre." — Chambers Canada
In his wide-ranging practice, Will has appeared as counsel in many important cases focusing on issues of public law and commercial litigation. He is also a leading practitioner of libel and media law, having acted for both plaintiffs and defendants in numerous noteworthy cases. In addition, he has acted as counsel to several Ontario universities.
From 2005 to 2008, Will was Canada's Associate Deputy Minister of Justice, with responsibility for civil litigation, national security and issues involving federal central agencies. He led a Department of Justice team that addressed a complex series of issues surrounding the Aboriginal Days of Protest in 2006–2007.
Upon his return to private practice in 2008, Will was appointed by the Chief Justice of Ontario to mediate issues arising from the Truth and Reconciliation Commission Inquiry into Aboriginal residential schools. He was subsequently appointed to an Amicus role by the Superior Court in connection with a series of land occupations in Brantford. In 2009 he was named Chief Commission Counsel to the City of Mississauga Judicial Inquiry, which delivered its report in October 2011.
Will was a joint recipient of the Department of Justice National Award for his work in resolving the high-profile Maher Arar v Canada case. He has also been honoured by the University of Toronto for many years of volunteer efforts on behalf of his alma mater. A frequent contributor to professional conferences as a speaker as well as a writer, he has taught trial advocacy at Queen's University and Osgoode Hall law schools.
Will was elected in May 2023 to serve his third term as a Bencher of the Law Society of Ontario.
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Paterson v Royal Bank of Canada
Counsel to the defendants in a $275 million defamation claim. Successfully brought a motion to strike the claim on the basis that it was an abuse of process and barred by the Ontario Limitations Act. Reported at 2025 ONSC 1122.
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Counsel to the plaintiffs in successfully bringing a motion for summary judgment, finding a valid and enforceable agreement of purchase and sale, and awarding specific performance, which was upheld on appeal.
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Counsel to the plaintiffs/respondents, Benny Marotta and Solmar Development Corp., in a defamation action. Successfully resisted an anti-SLAPP motion, which sought to dismiss the claim.
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Xavier Tu v Ireland Byrne et al
Counsel for the Defendants in a defamation action.
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Successful counsel to a defendant/moving party in a motion to strike a statement of claim, which sought $2,000,000 in damages for defamation. Despite being an opposed motion in-writing, the Superior Court of Justice granted the motion and awarded costs.
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The Corporation of the City of Kingston v Jason English et al
Counsel to the City of Kingston in an application for a permanent injunction which involved a Charter Challenge to one of its by-laws.
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1107051 Ontario Ltd v GG Kingspa Enterprises Limited Partnership
Counsel to Great Gulf in a large commercial dispute involving the development of two large condominium projects in the heart of downtown Toronto. Great Gulf successfully resisted the Plaintiffs’ motion to strike claims for repudiation made in Great Gulf’s counterclaim.
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Counsel to York University in judgment enforcement proceedings arising from a multi-million dollar fraud against the University. Most recently, successfully resisted an application by a judgment debtor which sought to drawn down equity in assets available to York for enforcement purposes.
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Counsel to the Mayor of Mississauga in various proceedings initiated by a former member of Council.
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Town of Collingwood Judicial Inquiry
Counsel to the Town of Collingwood in a Judicial Inquiry into the 50% share sale of Collingwood Utility Services Corporation to PowerStream Inc.
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American College of Trial Lawyers - Fellow
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Law Society of Ontario - Bencher (2011–2019;2023-present)
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The Advocates' Society - Member; Former Director
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Canadian Bar Association
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Ontario Bar Association
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Alliance Française de Toronto
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University of Toronto Summer Institute in Advocacy - Founding Co-Chair
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Laskin Moot - Director
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Instructions to Spies: Are They Privileged?
In brief, the decision by Justice Boswell of the Commercial List suggests that solicitor/client privilege has been narrowed, and litigation privilege has become easier to lose. For seven years, Catalyst Capital and West Face Capital have been at war. Their latest skirmish, over privilege, might change the way that lawyers interact with witnesses, investigators, and the media.
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In 2017, the Canada Food Inspection Agency (the “CFIA”) determined that wines produced by Psagot Winery, a vineyard located within an Israeli settlement in the West Bank, could be sold in Canada with a “Product of Israel” label to meet “country of origin” labelling requirements required under the Consumer Packaging and Labelling Act and the Food and Drugs Act. This decision was challenged by Dr. David Kattenburg, a Canadian activist, on the basis that the wine was in fact produced on occupied Palestinian territory and not within Israel, making the labelling of “Product of Israel” false and misleading and therefore contrary to the applicable legislation.
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Supreme Court of Canada Provides First Guidance on the Test for an Anti-SLAPP Motion
The Supreme Court of Canada has released its highly anticipated pair of decisions, 1704604 Ontario Ltd v Pointes Protection Association and Bent v Platnick, which consider the anti-SLAPP framework set out in s 137.1 of the Ontario Courts of Justice Act (“CJA”) for the first time.
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When Must an Anti-SLAPP Motion Be Heard?
Ontario’s Anti-SLAPP legislation (ss 137.1 to 137.5 of the Courts of Justice Act) provides a judicial screening device. It is designed to swiftly eliminate claims that unduly limit freedom of expression on matters of public interest. Since coming into force, courts have considered, at length, the substantive issues. To date, little guidance has been provided on the procedural issues.
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Towards a More Workable Approach: Proportionality and Internet Defamation
As the internet continues to develop into the primary forum for expression in our society, defamation actions increasingly involve comments made online.
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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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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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Recent Canadaland-WE Charity Ruling Example of Anti-SLAPP ‘Misuse’ Says Lawyer
William C. McDowell was interviewed by Law Times, where he comments on the Court’s decision to dismiss the anti-SLAPP motion in Kielburger v Canadaland Inc, in favour of our client.
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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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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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Chambers Canada Recognizes Lenczner Slaght as a Top-Tier Litigation Firm
Canada’s leading litigation firm and its expert litigators continue to be recognized by world-renowned directory, Chambers & Partners.
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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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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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2023 Snapshot: Through the Lens of Lenczner Slaght
Lenczner Slaght launches our 2023 Snapshot, a look at the most significant developments, decisions, business takeaways, and trends in litigation from the last year, across 15 practice areas. Revisit 2023 and look ahead to 2024 through the lens of our expert litigators.
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18th Annual Civil Litigator’s Survival Guide To Evidence
William C. McDowell was invited to share his expertise at OsgoodePD's annual conference on key evidentiary principles and strategies. In the session, Evidentiary Issues on Motions and Applications: Perspectives from Both Sides of the Bench, William discussed the key differences between motions and applications, strategies for effective written motions and applications, guidance on avoiding common mistakes in evidence gathering and preparation on motions and applications (including summary judgment motions), and tips on evidence gathering during a case-conference.
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The 17th Annual Civil Litigator's Survival Guide to Evidence
William C. McDowell was invited to share his expertise at OsgoodePD's annual conference on Evidence Law Top Tips and Tricks. The conference gave attendees the practical tips and knowledge needed to prevail in negotiations, discoveries, motions, pretrials and trials.
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Leading Your Case: Opening Statements and Exam-in-Chief
Will McDowell shared his expertise at The Advocates' Society's program on the panel Telling Your Story: Choosing the Theory of the Case and Your Theme.
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Thomas G. Heintzman, OC, QC: Life at full speed
William C. McDowell's article Thomas G. Heintzman, OC, QC: Life at full speed was published in the Summer 2020 Issue of The Advocates' Journal. The article is a tribute to the late Thomas G. Heintzman, OC, QC.
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Keeping Up with the Times: How to Survive and Thrive in the Age of Digital Litigation
William C. McDowell was a faculty member at the 2018 Ontario Bar Association’s Institute. With his depth of expertise and experience in Defamation & Media Law, he discussed "The Impact of Social Media on the Development of the Law".
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Your Profession, Your Future: The Future of Media and the Law
William McDowell was a panelist at The Advocates' Society's program on how to manage the media in high profile cases, how to take a business... -
John Furlong, Laura Robinson and Qualified Privilege
William McDowell participated in a podcast entitled "John Furlong's Privilege", along with Jesse Brown of Canadaland, regarding John Furlong, Laura... -
Advanced Administrative Law and Practice
William McDowell was a guest speaker at the the Canadian Institute's Advanced Administrative Law and Practice conference. William spoke on ethics and...
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Benchmark Canada (2012-2025)
Litigation Star – Commercial, Government & Regulatory
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Benchmark Canada (2019)
Medical Defense/Health Attorney of the Year
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Best Lawyers in Canada (2013-2025)
Administrative & Public Law, Class Action Litigation, Corporate & Commercial Litigation, Defamation & Media, Health Care Law, Legal Malpractice Law
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Best Lawyers in Canada (2023)
Toronto "Lawyer of the Year" in Administrative & Public Law
Toronto "Lawyer of the Year" in Defamation and Media Law
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Canadian Legal Lexpert® Directory (2012-2025)
Litigation - Corporate Commercial, Litigation - Defamation & Media, Litigation - Regulatory & Public Law, Professional Liability, Litigation - Public Law (2023), White Collar Defence & Investigations
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Chambers Canada (2020-2025)
Litigation: Administrative & Public Law (Ontario)
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Department of Justice National (2011)
Award for his work in resolving the Maher Arar v Canada case
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Lexology Index: Canada (2013-2025)
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Lexology Index: Litigation (2018-2020)
Leading Lawyer
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Lexpert Guide to the Leading US/Canada Cross-border Litigation Lawyers in Canada (2013-2018)
Corporate Commercial Litigation, Defamation & Media Litigation
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