Lawyers
Matthew Sammon

About

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T416-865-3057

M416-262-4154

Emsammon@litigate.com

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Expertise

Practice Areas:
Bar Admissions:
- Ontario (2002)
Education:
- University of Toronto (2001) JD (Honours Standing)
- University of Toronto (1998) MA
- Carleton University (1997) BA (Highest Honours)

Details

Bio
Cases
Associations
Blog Posts
News & Media
Publications & Presentations
Recognition

Matthew Sammon

is a partner at Lenczner Slaght.

"Matt Sammon is a warrior of a litigator. He is fearless and takes on strong cases." — Chambers Canada

Recognized as a leading and formidable trial counsel, Matthew has extensive litigation experience across a broad range of areas, including complex corporate and commercial litigation, professional liability and medical malpractice, and employment cases.

After 20 years of practice at Lenczner Slaght, Matthew is now one of the most experienced civil trial lawyers of his generation, having conducted trials, applications, and arbitrations in myriad areas, including infrastructure and construction, complex commercial proceedings, insurance, medical litigation, professional liability, and employment disputes.

Matthew's experience as lead counsel for constructors in complex infrastructure and construction disputes in Ontario and other jurisdictions has earned him recognition as one of Canada's leading infrastructure lawyers.

His roster of clients has included large and mid-sized corporations across a wide range of sectors, including construction, financial services, insurance, banking, telecommunications, retail, health care, manufacturing, hospitality, and oil and gas. He also acts regularly for executives and other individuals in civil and regulatory disputes.

Matthew also has deep experience in professional regulation and medical malpractice litigation, appearing regularly as lead counsel in complex medical litigation and regulatory proceedings.

Chief James Marlowe and the Lutsel K’e Dene First Nation v Mirza Mohammad Imran Karim Barlas et al

Counsel to the Lutsel K’e Dene First Nation and its elected chief in an oppression application (and related injunction) arising from allegations of breach of fiduciary duty, misappropriation, and fraud by the CEO of the First Nations’ company.

Matthew Sammon, Jaan Lilles, Jessica Kras & Angela Hou | March 1, 2024

Mittra v Royal Bank of Canada et al

Counsel to RBC in this $10 million wrongful dismissal claim. After a three-week trial, the Court held that RBC had just cause to dismiss the plaintiff without notice. Reported at 2024 ONSC 636.

Matthew Sammon, David Salter & Solomiya Zakharchuk | January 29, 2024

Ratz-Cheung v BMO Nesbitt Burns Inc

Counsel to the defendants, Bank of Montreal, against a former employee in a matter involving damages for breach of contract and wrongful dismissal.

Matthew Sammon, Aoife Quinn & Sam Hargreaves | January 8, 2024

Grant Edey v Khan Resources

Counsel to former CEO and director for breach of employment agreement, and defence to counterclaim alleging unauthorised transactions.

Matthew Sammon & Christopher Yung | January 1, 2024

Commercial Arbitration

Counsel to a property development company in a dispute regarding the sale of a partnership interest.

Matthew Sammon, Sean Lewis & Evan Linn | January 1, 2024

Costco Wholesale Corporation v TicketOps Corporation

Counsel to the applicant in a successful application to have American arbitral awards and court judgments recognized and enforced in Ontario.

Matthew Sammon & Nikolas De Stefano | January 1, 2023

Crosslinx Transit Solutions Constructors

Counsel to consortium of construction companies building Eglinton Crosstown Light Rapid Transit line.

Lynne McArdle & Matthew Sammon | January 1, 2023

College of Physicians and Surgeons of Ontario v Cheng

Counsel to the Defendant Physician in successfully defeating claims of sexual abuse of a patient at a trial before a panel of the Ontario Physicians and Surgeons Discipline Tribunal.

Matthew Sammon & Brendan F. Morrison | May 4, 2022

Assurant Life of Canada ats GFD

Counsel to the successful Respondent corporation in a breach of contract dispute concerning an alleged amendment to a contract.

Matthew Sammon & Sean Lewis | February 1, 2022

Zimmerman v McNaull

Counsel to Respondent Physicians in a successful interlocutory motion, seeking a declaration that the Plaintiffs had impliedly waived privilege over information upon which they relied for their motion to add the Respondent Physicians to the Plaintiffs’ action after the presumptive expiry of the limitation period.

Matthew Sammon & Derek Knoke | July 27, 2021

Crosslinx v Metrolinx

Counsel to Crosslinx Transit Solutions Constructors in an application against Metrolinx and Ontario Infrastructure (HMQE) in relation to HMQE’s failure to declare an emergency as a result of the COVID-19 pandemic. Crosslinx is a design and construction consortium established to deliver and maintain the Eglinton Crosstown LRT, the second largest Canadian transit infrastructure project. We successfully resisted a motion to stay and succeeded entirely on the application to obtain contractual relief due to the pandemic. This is notable as it may have broader implications for other P3 Projects across the province of Ontario.

Matthew Sammon, Andrea Wheeler, Jacqueline Chan, Andrew Parley, Scott Rollwagen, Christina Shiels-Singh & Paulina Goncalves | January 1, 2021

Construction Arbitration

Counsel to a general contractor in respect of a complex mediation/prospective arbitration process regarding a subway extension project.

Matthew Sammon, Andrew Parley, Andrea Wheeler, Aaron I. Grossman, Scott Rollwagen, Sarah Millar & Christina Shiels-Singh | August 30, 2019

Zanardo v Di Battista

Counsel to the applicant Estate Trustee in a successful oppression application, and on appeal. The application judge ordered the wind up of the respondent corporation, based on grave breaches of fiduciary duties by the personal respondents, including the usurpation of a significant real estate opportunity. The divisional court affirmed the application judge’s remedy and findings.

Matthew Sammon, Christopher Trivisonno, Sam Johansen & Melissa Baur | February 27, 2019

Construction Dispute

Counsel to a general contractor in a dispute with a design subcontractor on a very large transit project regarding design deficiencies and payment for design changes that have arisen over the course of construction.

Matthew Sammon, Andrew Parley, Aaron I. Grossman, Kelly Hayden, Christina Shiels-Singh & Megan Bradt | January 1, 2019

Aecon Mining Construction Services v K+S Potash Canada GP

Counsel to Aecon in complex litigation involving multiple parties and claims, in respect of the Legacy potash mine and production facility in Saskatchewan.

Matthew Sammon, Sarah Millar, Andrew Parley, Aaron I. Grossman, Margaret Robbins, Kate Costin, Sean Lewis, Andrew Locatelli, Blerta Gjoci & Christina Shiels-Singh | January 1, 2019

Bourque v Cineflix

Counsel to Cineflix and related entities in a proposed class action relating to the alleged misclassification of independent contractors in the television production industry.

Matthew Sammon, Paul-Erik Veel, Margaret Robbins & Christina Shiels-Singh | October 1, 2018

Rutman v Rabinowitz

Counsel to the respondent on an appeal in a seminal internet defamation case. The Court of Appeal for Ontario clarified the law of concerted action liability and upheld a very large damages awards for what it characterized as a prolonged, persistent and vicious internet campaign.

Matthew Sammon & Jessica Roher | February 6, 2018

Breton v Fairley

Counsel to the defendant physician in a medical negligence trial relating to the performance of a laparoscopy and vaginal resection.

Matthew Sammon & Andrea Wheeler | June 18, 2016

Estate Trustee During Litigation for the Estate of Paul Penna v Landen

Counsel to Estate Trustee During Litigation of the Paul Penna Estate in a series of proceedings, including two appeals to the Ontario Court of Appeal and a contempt trial, arising out of a massive fraud perpetrated by former Estate Trustee in his administration of the Estate.

Peter Griffin & Matthew Sammon | April 7, 2001

Die-Mold Tool Ltd v McKenzie

Counsel to a corporate plaintiff in a complex series of disputes involving the alleged oppressive conduct of a departing executive.

Matthew Sammon | January 13, 2001

Sazant v College of Physicians and Surgeons of Ontario

Counsel to intervener physicians in a constitutional challenge to a provision of the Regulated Health Professions Act.

Tom Curry, Matthew Sammon & Jaan Lilles | January 12, 2001

Cytrynbaum v Look

Counsel to defendants/applicants, Michael Cytrynbaum and First Fiscal Management Ltd., in an application, and on appeal, for advancement of legal expenses in an action alleging breach of fiduciary duties and unjust enrichment in connection with the sale of a company's assets.

Peter Griffin & Matthew Sammon | December 21, 2000

Thompson v Sehgal

Counsel to the defendants physicians in a medical negligence proceeding, including on a motion for summary judgment on the basis that the limitation period had expired.

Matthew Sammon | November 25, 2000

Rowley v High Strength Plates &Profiles Inc

Counsel to the defendant in a wrongful dismissal proceeding. The defendant was successful in resisting plaintiff's allegations of constructive dismissal.

Matthew Sammon & Brendan F. Morrison | November 14, 2000

Re Cal Jet Performance Inc

Counsel for the respondent in a bankruptcy proceeding regarding sections 37 and 38 of the Bankruptcy and Insolvency Act.

Matthew Sammon | September 23, 2000

Davies v Satellite Radio Inc

Counsel for the plaintiff in a constructive dismissal trial.

Matthew Sammon | September 22, 2000

Mackie Research Capital Corporation v Mackie

Counsel for the plaintiffs in a dispute relating to the departure of investment advisors. The defendants were alleged to be in breach of their fiduciary duties as well as various contractual post-employment covenants.

Matthew Sammon, Paul-Erik Veel & J. Gwendolyn Ward | September 21, 2000

Bikur Cholim Jewish Volunteer Services v Langston

Counsel in an appeal addressing complex limitation issues in an estate proceeding.

Matthew Sammon | August 23, 2000

Bourque v St Joseph Health Centre

Counsel for the successful defendant physicians in the trial of a medical malpractice matter relating to injuries alleged suffered during surgery.

Matthew Sammon | August 16, 2000

McKee v Health Professions Appeal and Review Board

Counsel to a physician on a successful judicial review application to quash the decision of the Health Professions Appeal and Review Board.

Matthew Sammon | August 1, 2000

Gratzki v Estate of Clark

Counsel for the defendant estate in a medical malpractice case. Action dismissed without costs on consent after four days of trial.

Matthew Sammon | July 21, 2000

Kelly v Ontario

Counsel for a physician in disciplinary proceedings. Included an application for various relief on constitutional grounds and a constitutional challenge to a provision of the Regulated Health Professions Act.

Matthew Sammon | July 15, 2000

Road Trailer Rentals Inc v Robinson

Counsel to a defendant in an employment matter. Successfully opposed a motion for an interlocutory injunction.

Matthew Sammon | July 4, 2000

Dufour v Kim

Counsel for the successful defendant in a medical negligence jury trial.

Matthew Sammon | June 30, 2000

Diaczuk v Holloway

Counsel to the defendant physician in a medical malpractice case relating to an injury sustained during the delivery of a baby. Successful in defending the action at trial.

Matthew Sammon | June 25, 2000

Meady v Greyhound Canada Transportation Corp

Counsel for a physician in an action relating to a bus crash that had occurred as a result of conduct of a patient. Successful in opposing a motion to add the physician to the action, and in precedent-setting appeal regarding the interpretation of the Limitations Act, 2002 and the doctrine of special circumstances.

Matthew Sammon | June 21, 2000

Re 1231640 Ontario Inc

Counsel to a creditor in complex insolvency/receivership matter regarding the priority of secured creditors' interests.

Matthew Sammon | June 15, 2000

Dodd v RBC Dominion Securities Inc

Counsel for the defendants in a trial regarding an alleged negligent misrepresentation with respect to a commercial venture. Successful in defending the action.

Matthew Sammon | June 10, 2000

Katzman v Royal College of Dental Surgeons of Ontario

Counsel on a successful motion by the defendant to determine questions of law and strike out portions of the plaintiff's claim on the basis of absolute privilege and the Regulated Health Professions Act.

Matthew Sammon | May 26, 2000

Wadsworth v RBC Dominion Securities

Counsel to the defendants on a successful motion for summary judgment in an employment matter. Counsel for the respondent on appeal.

Matthew Sammon | May 11, 2000

Giroux Estate v Trillium Health Centre

Counsel to a physician in a medical negligence action, which included an appeal dealing the doctrine of fraudulent concealment and the limitation period applicable to claims by estates.

Tom Curry & Matthew Sammon | May 7, 2000

Blanchard v Sherstan

Counsel for the successful defendant in a medical malpractice case.

Matthew Sammon | May 4, 2000

Operation 1 Inc v Phillips

Counsel to a defendant in an action relating to the exercise of a power of sale on a mortgage. Successful motion to set aside Anton Piller and Mareva injunctions.

Matthew Sammon | May 3, 2000

Joseph v Lefaivre Investments (Ottawa) Ltd

Counsel to the defendant in a class on a motion to transfer a class proceeding to a different venue.

Matthew Sammon | May 2, 2000

Reid v Livingstone

Counsel to defendant physicians in a medical malpractice action relating to management of pain during labour and delivery. Successful motion for summary judgment.

Matthew Sammon | April 12, 2000

Ng v Richmond York Developments

Counsel to the plaintiff in a real estate dispute. Successfully moved to register a certificate of pending litigation.

Matthew Sammon & Jaan Lilles | April 10, 2000

McPherson v Scully

Counsel to the successful plaintiff in a trial relating to a breach of contract regarding the construction of nursing homes in Ontario.

Matthew Sammon | April 6, 2000

Canada (Information Commissioner) v Canada (Minister of the Environment)

Counsel to Ethyl Canada in an appeal to the Federal Court of Appeal regarding the interpretation of the Access to Information Act and cabinet document privilege.

Matthew Sammon | March 31, 2000

Re PSINet Ltd

Counsel to a US parent company in cross-border insolvency proceedings respecting priority of the parent's inter-company claim/re-registration of lapsed security.

Peter Griffin & Matthew Sammon | March 26, 2000

Tzembelicos v Tzembelicos

Counsel in an application for partition and sale of partnership property and a counter-application for a winding-up or for an auction and appraisal process to separate the partners. Successful in resisting the application and imposing an auction process.

Matthew Sammon | March 25, 2000

Canadian Bar Association
Ontario Bar Association
The Advocates' Society

Court Puts Bankers on Notice: “Exceptional” Integrity and Honesty Required

After a three-week trial, the Ontario Superior Court has held that the Royal Bank of Canada had after-acquired cause to terminate a senior banker, Aidan Mittra, and dismissed Mittra’s $10‑million lawsuit.

Matthew Sammon & David Salter | February 21, 2024

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.

November 21, 2024

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.

September 26, 2024

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.

August 29, 2024

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.

March 5, 2024

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.

November 23, 2023

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.

September 28, 2023

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.

August 24, 2023

Lenczner Slaght’s Litigation Excellence Recognized in 2023 Lexpert Directory

Following comprehensive peer review surveys and interviews with senior members in the legal profession, the 2023 Canadian Legal Lexpert Directory has recognized 31 of the firm’s expert litigators for their experience, knowledge, and precision, with 108 rankings spanning 17 practice areas.

March 1, 2023

Lenczner Slaght Recognized Among Canada’s Leading Litigation Lawyers

Following an in-depth peer review process, the 2022 Lexpert Special Edition: Canada's Leading Litigation Lawyers guide recognizes 15 Lenczner Slaght lawyers for their extensive courtroom experience and subject-matter expertise. We know courts, and courts know and trust us. That is why clients turn to us to solve their most complex legal problems.

November 23, 2022

Lenczner Slaght Stands Out as a “Litigation Powerhouse” in Legal 500 Canada

Canada’s leading litigation firm is once again ranked in Tier 1 for Dispute Resolution by Legal 500 Canada.

November 10, 2022

Civility in a Post-Pandemic Era

Matthew Sammon presented at The Advocates' Society's program Civility in a Post-Pandemic Era on the panel "Litigator v. The Courtroom: Scenarios for Discussion".

Matthew Sammon | December 15, 2020

Your First Civil Trial

Matthew Sammon spoke at the OBA's Young Lawyers Division program Your First Civil Trial. He shared his expertise on the panel “Top 10 Trial Mistakes and How to Avoid Them".

Matthew Sammon | March 6, 2020

Defamation in the Social Media Sphere

Matthew Sammon spoke at the Ontario Bar Association's program Social Media and Internet Law: Your Comprehensive Guide. He shared his expert insight on the social media landscape and how to keep pace with this evolving area of the law.

Matthew Sammon | October 15, 2018

Beyond Contractual Borders: Managing the Recruitment and Departure of Senior Executives and Employees

Matthew Sammon and Risa Kirshblum spoke at the 2018 National Conference & World Summit. This panel of employment litigators and experienced in-house counsel shared practical tips on topics including non-competition and non-solicitation provisions, confidentiality obligations, employees duties’ to former employers and steps to respond to and manage improper departures.

Matthew Sammon & Risa M. Kirshblum | May 1, 2018

When Family Law Collides: Essential Interdisciplinary Issues

Matthew Sammon was a faculty member at the 2018 Ontario Bar Association’s Institute. He shared his valuable insight on the panel "Closely-Held Corporations: Dealing with Oppression."

Matthew Sammon | February 9, 2018

36th Annual Intensive Trial Advocacy Workshop

Lawrence Thacker, Risa Kirshblum, Monique Jilesen, Eli Lederman, Matthew Sammon, Rebecca Jones, Jaan Lilles and Dena Varah were among the distinguished...

July 5, 2015

Managing Employment Law Issues in the Digital Age

Matthew Sammon co-chaired the OsgoodePD program Managing Employment Law Issues in the Digital Age on April 20, 2015, in which Jaan Lilles...

Matthew Sammon, Jaan Lilles & Dena N. Varah | April 20, 2015

Practical Tools to Reduce your Organization's Risk with Social Media Use

Matthew Sammon, Jaan Lilles and Dena Varah conducted a webinar as part of the Canadian Corporate Counsel Association/Canadian Bar Association's Webinar Series on October 17, 2014 from 12:00pm to 1:30 pm.

Matthew Sammon, Dena N. Varah & Jaan Lilles | October 17, 2014

10th Annual Update on Personal Injury Law and Practice

Matthew Sammon spoke at OsgoodePD's 10th Annual Update on Personal Injury Law and Practice.

Matthew Sammon | September 30, 2014

The future of unconventional restrictive covenants

Matthew Sammon's article The future of unconventional restrictive covenants appeared in the July 11, 2014 issue of the Lawyers Weekly."The recent case...

Matthew Sammon | July 11, 2014

Benchmark Canada (2015-2024)

Litigation Star – Commercial, Professional Liability

Benchmark Canada (2019)

Labour Employment Attorney of the Year

Best Lawyers in Canada (2014-2025)

Corporate & Commercial Litigation, Health Care Law, Labour & Employment Law, Medical Negligence

Best Lawyers in Canada (2022)

Toronto "Lawyer of the Year" in Medical Negligence

Canadian Legal Lexpert® Directory (2013-2024)

Litigation - Corporate Commercial, Medical Negligence, Professional Liability, Litigation - Defamation & Media (2021), Employment Law (Employer) (2021)

Chambers Canada (2020-2025)

Construction; Employment & Labour: Non-Unionised Employees; Healthcare: Contentious (Nationwide – Canada)

Lexpert Guide to the Leading US/Canada Cross-border Litigation Lawyers in Canada (2014-2017)

Corporate Commercial Litigation, Litigation Lawyer to Watch (2014)

Lexpert Rising Stars (2013)

Leading Lawyers Under 40

Lexpert Special Edition: Canada's Leading Health Sciences Lawyers (2021)

Lexpert Special Edition: Canada's Leading Infrastructure Lawyers (2020-2024)