About Catherine
Cathy litigates complex commercial and regulatory cases and defends class actions with a regulatory component. She is currently defending clients in multiple privacy, antitrust, insurance, product liability, misleading advertising, telecommunications and consumer-protection class actions. Cathy also acts as breach counsel for clients experiencing a data breach or cybersecurity incident.
Cathy has appeared before the Supreme Court of Canada in 18 appeals, including arguing leading commercial, constitutional, privacy and freedom of information appeals. She is a former law clerk to the late Chief Justice of Canada, the Right Honourable Antonio Lamer.
Cathy’s national litigation practice has involved arguing before the trial courts of every province, in addition to appellate courts across Canada and a wide range of administrative and arbitration tribunals. She has represented the House of Commons before Commissions of Inquiry and has been counsel to and given evidence to provincial and federal legislative committees.
Cathy is the co-Practice Group Leader of the Toronto Litigation group and also leads Blakes National Cybersecurity Working Group. She served on the Firm's Executive Committee from 2015 to 2020.
Class Actions
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Represents an insurer in class actions across the country relating to business interruption claims in the context of the COVID-19 pandemic
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Succeeded in having certification dismissed in the Casino Rama and Rouge Valley Hospital privacy class actions, and is also counsel to quick service restaurant chains, a website and app and automotive manufacturers in class actions relating to alleged privacy breaches
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Defending automobile manufacturers and pharmaceutical companies in product liability class actions
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Counsel in numerous antitrust class actions, including proceedings relating to packaged bread, computer operating systems, polyether polyols, hydrogen peroxide, chocolate, LCD panels, optical disk drives, SRAM and CRT
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National counsel for Merck & Co. and Merck Frosst with respect to the Vioxx class actions commenced across Canada
Appellate Advocacy
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Lead counsel for intervenors in C.M. Callow Inc. v. Zollinger, 2020 SCC 45, one of the most significant commercial cases of 2020, which clarified the good faith duty of honest performance of contracts
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Lead counsel for a consortium of Canada's largest energy producers in Reference re Environmental Management Act, 2020 SCC 1, one of the most significant constitutional cases of 2020, regarding limits on British Columbia’s jurisdiction over the Trans Mountain pipeline expansion project
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Lead counsel to the successful appellant in Royal Bank of Canada v. Trang, the leading Supreme Court of Canada decision interpreting Canada's private-sector privacy legislation
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Lead counsel to Merck in Merck Frosst Canada Ltd. v. Canada (Health) with respect to the confidentiality of third-party information requested under the Access to Information Act
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Lead counsel for TELUS before the Ontario Court of Appeal in a challenge to provincial legislation seeking to regulate wireless services agreements (appeal pending)
Cathy has been recognized as one of the Top Women in Litigation in Canada for eight consecutive years by Benchmark. She is also recognized as a leading litigation lawyer in the following publications:
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The Best Lawyers in Canada (2024–2025: Administrative and Public Law, Class Action Litigation, Director and Officer Liability Practice; 2023–2025: Appellate Practice, Corporate and Commercial Litigation, Privacy and Data Security Law)
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Chambers Canada Legal Guide (2024–2025: Privacy & Data Protection – Nationwide; 2023–2025: Litigation: General Commercial – Ontario; 2022–2025: Dispute Resolution: Class Action (Defence) – Nationwide)
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Thomson Reuters Stand-out Lawyers – Independently Rated Lawyers – 2024–2025 (As nominated by senior in-house counsel)
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Lexology Index Thought Leaders: Healthcare & Life Sciences 2025 (Product Liability Defence)
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Lexology Index: Data – 2023–2025 (Data – Data Privacy & Protection)
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The Canadian Legal Lexpert Directory (2023–2025: Litigation – Product Liability; 2022–2025: Data Protection & Privacy; 2021–2025: Competition Law, Class Actions, Litigation – Regulatory & Public Law; 2021–2024: Litigation – Corporate Commercial)
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Benchmark Canada: The Definitive Guide to Canada's Leading Litigation Firms and Attorneys (2023, 2025: Litigation Star – Class Action, Commercial, Competition/Antitrust, Product Liability and Recall)
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Lexpert Special Edition: Litigation 2024
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Lexpert Special Edition: Technology and Health Sciences 2024
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Lexology Index: Commercial Litigation – 2023–2024
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The Legal 500 Canada (2024: Hall of Fame – Dispute Resolution: Ontario; 2023: Dispute Resolution: Ontario; 2022: Dispute Resolution)
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Lexology Index: Canada (2022–2024: Commercial Litigation; 2021–2024: Data, Product Liability Defence; 2021, 2023–2024: Life Sciences)
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Lexology Index: Product Liability Defence – 2021, 2023–2024
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Lexology Index: Life Sciences – 2021, 2023–2024 (Life Sciences – Product Liability)
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Lexpert Special Edition: Litigation 2023
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Benchmark Canada's Top 100 Women in Litigation 2023
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Benchmark Canada's Top 50 Women in Litigation 2022
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Best Lawyers: "Lawyer of the Year" 2022 (Privacy and Data Security Law)
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Lexology Index: Thought Leaders 2021 (Data – Data Privacy & Protection)
Cathy taught a course on privacy and freedom of information at Osgoode Hall Law School from 2000 to 2008. From 1997 to 1998, she was law clerk to The Right Honourable Antonio Lamer, P.C., C.C., Chief Justice of Canada.
In 2019–2020, Cathy chaired the Investment Committee of Women United, a United Way initiative empowering women to build strong, independent lives.
- Co-author : Canadian Court Strikes Plaintiffs’ Expert Evidence, Denies Certification of Pharmaceutical Class Action
Blakes Bulletin on Class Actions, June 12, 2023. - Co-author : Protecting Your Organization from Ransomware Threats: New Guidance from Ontario’s Information and Privacy Commissioner
Blakes Bulletin on Cybersecurity, October 27, 2022.
- Co-speaker : Protect, Prepare, Prevail: Navigating a Complex Cybersecurity World
Episode 34, Blakes Sound Business Podcast, December 17, 2024. - Speaker : Data Breaches and Cybersecurity Law 101, Osgoode Certificate in Privacy and Cybersecurity Law
Osgoode Professional Development, Toronto, Ontario, February 29, 2024. - Speaker : Admissibility of Electronic Evidence
Alberta Provincial Judges' Association and Society of Justices of the Peace for Alberta 2023 Spring Conference, Canmore, Alberta, May 19, 2023. - Speaker : Safety Net (from Cyber Attacks)
Financial Post, Toronto, Ontario, March 29, 2023. - Co-chair : Digital Evidence for Litigators
The Advocates' Society, Toronto, Ontario, March 28, 2023. - Speaker : Privacy Class Actions in Canada: Recent Trends
Blakes Business Class Webinar, September 13, 2022.
- Quoted : SCC rules CRTC has no jurisdiction to decide 5G access disputes between telecoms and municipalities
Article by Cristin Schmitz, Law360 Canada, April 25, 2025
Admitted to the Ontario Bar – 2000
LLM, Harvard Law School – 1999
LLB (Gold Medallist), Osgoode Hall Law School, York University – 1997
BA, University of Prince Edward Island – 1994
