Sophie Perreault

Lawyer, Partner - Montréal

Québec Bar 1994
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Sophie is an accomplished litigator and is recognized for her ability to lead complex files in a wide range of commercial disputes, penal procedures and regulatory proceedings. She has an impressive record in extraordinary proceedings such as injunctions, mandamus proceedings and Anton Piller orders. She has also acted in defence in class action proceedings and in constitutional matters that have been pleaded before the Supreme Court of Canada.

In addition to her litigation practice, Sophie assists her clients in managing their business challenges, particularly in the areas of ethics, anti-corruption and directors’ and officers’ liability. She advises them in the assessment and management of legal, operational, and reputational risks and participates in the development of compliance policies and programs, internal and external investigations, as well as the defence and negotiation of lawsuits by governmental and regulatory authorities. She has particular expertise in integrity requirements for public contracts and also practices in environmental law.

A trailblazer in the legal community and a great mentor for our firm’s younger lawyers, Sophie has earned the trust and respect not only from clients, but also from opposing counsel and the judiciary for her outstanding management of all aspects of the cases in which she is involved.

In 2022, Sophie was inducted as a Fellow of the American College of Trial Lawyers (ACTL) and she was appointed Vice Chair of the Quebec Province Committee. The ACTL is considered the preeminent organization of trial lawyers in North America, marking to a professional career characterized by the highest standards of ethical conduct, professionalism, civility, and collegiality. She was also recognized as a star of the legal profession in the Acritas Global Survey, having been named an Outstanding Lawyer by her clients and is listed in Canada’s most prestigious legal directories including Chambers CanadaThe Best Lawyers in CanadaBenchmark Litigation and The Canadian Legal Lexpert Directory.

Sophie is Chair of the Langlois Lawyers Board of Directors.


Mini-MBA Program, McGill Executive Institute, 2015-2016

B.C.L./LL.B., McGill University, 1993

Representative Work

Sophie is acting or has acted in the following matters:

– A construction company and certain shareholders: defending a $15M claim by another shareholder

– A public institution specialized in managing infrastructure projects: defending a constitutional challenge of the Act respecting the Réseau Électrique Métropolitain in connection with a project to build a $6 billion automated light rail transportation system in Montreal

– A petroleum company: in relation to multiple environmental, real estate and commercial disputes, including an action brought by a property owner seeking rehabilitation under the Quebec Environment Quality Act, which was dismissed by the Quebec Superior Court

– A Canadian communications company: in its $1.2 billion claim against the private equity sponsors of the failed leveraged buyout of the company

– A mining company: aggressive intervention in relation to Anton Piller proceedings in the context of fraudulent activities of third parties

– A paper company: in successfully obtaining an Anton Piller order and allowing repossession of the client’s property and data

– A Canadian communications company: defending a class action in the context of unilateral modifications of a consumer contract

– A biopharmaceutical company: in successfully obtaining injunction reliefs further to the departure of employees to a competitor

– A wholesale retailer: defending against a demand for a Norwich order

– A company in the agriculture and food industry: defending against a claim for damages for alleged defective product

– Public procurement: representing numerous clients in the context of the application of the integrity requirements (federal and provincial) and the obtention of mandatory authorizations to enter into public contracts

– Risk management: advising various clients on risk management, compliance and business ethics, particularly regarding crisis situations and imminent litigation risks




Other Publications

2019 – “The Autorité des marchés publics is the new actor in the Quebec public contracts regime”, co-authored with Justine Brien, Canadian Lawyer, April 30, 2019.

2015 – Government of Canada amends Integrity Regime: less debarment, but more suspension

2014 – Public contracts: overpayments targeted by the government (again)

2014 – Who is responsible for rehabilitation under the Quebec, Environment Quality Act

2014 – Quebec public contracts: AMF authorization required for contracts and subcontracts worth $5 million or more as of October 24

2013 – As of January 15, 2013, certain City of Montreal contracts are subject to the rules of the Integrity in Public Contracts Act

2012 – Bill 1 becomes law: doing business with the State is now a privilege that requires prior authorization

2012 – Quebec’s Bill 1: Priority 1 for enterprises doing business with the government

2012 – Extended warranties: merchants vindicated as seven proposed class actions are thrown out


Langlois Knowledge

External Conferences


Sophie is a regular guest speaker on topics pertaining to business ethics and anticorruption matters, environmental law and crisis management.

2023 – “Évolution du milieu du travail : les chemins, sont-ils vraiment plus flexibles?”, Panel moderator, La pratique en litige : Choisir son parcours, Symposium pour les femmes en litige 2023, The Advocates’ Society, Montréal

2019 – “L’Autorité des marchés publics – un nouveau joueur en matière de contrats publics”, Conference to clients, Montréal

2018 – “Cyberattaque: trousse juridique pour se préparer à l’inévitable”, RISIUQ, Quebec City

2017 – “Gestion de crise: prévention, préparation et réaction lorsque votre réputation est à risque”, Vision 2017, Montréal

2017 – “Cyberattaque: trousse juridique pour se préparer à l’inévitable”, GoSec 2017, Montréal

2016 – “Public Contracts: Integrity Requirements”, Montréal

2016 – “Démystifier les relations avec l’État Partie III – Intégrité et contrats publics”, Montréal

2016 – “Nouvelles exigences en matière de conformité et d’intégrité : gérez vos risques et démarquez-vous de vos concurrents”, Vision 2016, Montréal

2016 – “Exigences d’intégrité en matière de contrats publics”, Montréal

2015 – “La Loi sur l’intégrité en matière de contrats publics, deux ans plus tard“, Montréal

2013 – “Gestion de crise environnementale et en matière de santé et sécurité — Comment limiter les dégâts”, Montréal

2013 – “Prevention against fraud and corruption: latest legal developments”, Montréal

2013 – “Diffamation et gestion de crise”, Montréal


Guest lecturer, Civil Litigation Course, McGill University Faculty of Law

Former lecturer, Civil Pleading Techniques, Quebec Bar Admission Course

Former chair of the governing board, École Primaire Beaconsfield

Former member of the board of directors of the CPE de La Pointe

Professional Associations

Since 2023 –Vice Chair of the Quebec Province Committee, American College of Trial Lawyers

Since 2022 – Fellow of the American College of Trial Lawyers

Advocates Society

Canadian Bar Association

Fondation La Récréation, co-founder and chair of the board

Former member of the committee of the Quebec Bar on civil procedure reform

Former member of the committee on the future of the information in Quebec

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