Sarah Armstrong is the Chair of Fasken’s Ontario Litigation and Dispute Resolution Practice Group. An adept and strategic litigator, Sarah combines skilled courtroom advocacy and sound judgment to represent clients who are involved in business-critical disputes.
Sarah navigates clients through complex commercial disputes and professional liability matters in both court and in arbitration. In the class action arena, Sarah has extensive experience managing and coordinating the defence of overlapping and multi-jurisdictional proceedings in securities, product liability, privacy and cybersecurity, insurance coverage and consumer cases. Sarah advises organizations across a wide array of industries including mining, professional services, insurance, health, automotive, retail and manufacturing. Sarah acts as lead counsel at the trial and appellate levels as well as before domestic and international arbitral tribunals.
A Fellow of the American College of Trial Lawyers, Sarah is consistently recognized as a leading litigator by legal directories including Chambers and Partners, Benchmark Litigation, Best Lawyers, Legal 500 and the Canadian Legal Lexpert Directory. In 2026, Benchmark Litigation Canada recognized Sarah as one of Canada's Top 100 Women in Litigation. Based on its extensive research, Chambers reports that clients describe Sarah as having “exceptional judgement and [being] a fantastic oral advocate.” Sarah is also a Fellow of the Litigation Counsel of America and a member of the International Association of Defence Counsel (IADC).
Committed to promoting excellence in advocacy, Sarah is a frequent presenter and mentor with The Advocates’ Society, instructing fellow advocates on skills essential to class actions, commercial litigation, arbitration and advocacy. She has also been recognized for her volunteer contributions to the University of Toronto Faculty of Law and served as a Director of the University of Toronto Alumni Association.
Sarah dedicates significant time to pro bono work and co-chairs Fasken’s Ontario Pro Bono Committee. She also served as a Director and Chair of Pro Bono Ontario. Her advocacy for children with disabilities has helped address unlawful conditions that kept them out of school or without appropriate special education services. In recognition of her contributions to pro bono legal services, Sarah received the Ontario Bar Association’s David Scott Award for Pro Bono Law.
Representative Class Action Experience
Securities
- Representing Global Atomic Corporation in proposed securities class action
- Representing Guyana Goldfields in proposed securities class action
- Representing Gatos Silver in securities class action
- Representing Just Energy Group in securities class action
- Representing PricewaterhouseCoopers (US) in securities class action
- Representing Baja Mining Company in securities class action
- Representing Gammon Gold in securities class action
Insurance
- Representing Intact Insurance Company and related insurers in COVID-19 business interruption insurance class actions
- Representing Intact Insurance Company and related insurers in proposed class action relating to total loss auto insurance claims
- Representing Aviva, Co-operators and Gore in proposed class action relating to HST on accident benefits
Employment and Benefits
- Representing a major Canadian Schedule 1 bank in a holiday and vacation pay class action
- Representing a major Canadian Schedule 1 bank in a proposed employment class action
- Representing The Avon Company Canada and The Avon Company in post-retirement benefits class action
Products, Medical Device and Other Consumer Class Actions
- Representing Alterna Credit Union and Alterna Bank in class action relating to NSF fees
- Representing Advanced Bionics and related entities in medical device class actions
- Representing Cook Medical and related entities in medical device class actions
- Representing Hill’s Pet Nutrition in class action related to alleged defect in pet food
- Representing FGA Brands in class action involving deceptive marketing allegations about consumer product
- Representing Canon Canada Inc. in class action related to alleged product defect
- Representing Guidant Corp. in medical device class actions
Privacy and Cybersecurity
- Representing Laurentian University in privacy and cybersecurity class action
- Representing Google in privacy disputes
- Representing Capital One in privacy and cybersecurity class actions
- Representing Equifax in privacy and cybersecurity class action
- Representing a children’s aid society in a privacy and cybersecurity class action
Representative Commercial Litigation and Arbitration Experience
- Representing big four audit firm in its defence of multiple significant audit negligence actions
- Representing mining industry client in confidential ICC arbitration valued at C$220 million
- Representing applicant in confidential arbitration arising from post-closing purchase price dispute
- Representing auto parts manufacturer in breach of contract action against OEM
- Representing client in retail pharmacy industry in its defence of an executive wrongful dismissal action
- Representing client in successful motion to stay Ontario proceedings on basis of contractual jurisdiction clause
- Representing respondent in successful opposition to application for declaratory and other relief in dispute about patent rights
