Lawyer - Montréal
Guillaume Leahy practices civil and commercial litigation in the Montréal office of Langlois lawyers.
He acts primarily in complex litigation files involving product liability, constitutional law and contractual, civil or professional liability issues.
Guillaume advises businesses and organizations active in various industries including mining and metals, information technology, port operations, as well as construction and defends their interests before civil courts and administrative or arbitral tribunals. He frequently represents foreign clients, particularly in matters involving private international law.
In addition, he has acquired extensive expertise in supervising the work of expert witnesses and managing electronic evidence in litigation matters involving major commercial, strategic and economic issues.
Before joining Langlois lawyers, Guillaume practiced civil and commercial litigation at a national law firm.
Juris Doctor, Queen’s University, Kingston, Ontario, 2013
LL.B, Laval University, Québec, 2011
Rankings & Recognitions
Best Pair of Oralists and 4th Best Appeal Factum at the Laskin Moot, 2013
Agnes Lefas Memorial Scholarship, Queen’s University Faculty of Law, 2013
Honour Roll of Laval University’s Faculty of Law, 2011-2012
First prize at the “Face-to-Face” interuniversity debate competition, 2011
Winner of the Academic prize at the year-end gala of Laval University’s Faculty of Law, 2011
McCarthy Tétrault Leadership Award, Laval University’s Faculty of Law, 2010
Best Appeal Factum at the Pierre-Basile-Mignault civil law moot, 2010
Scholarship for academic excellence, Laval University’s Faculty of Law, 2009
Areas of Practice
Guillaume’s recent experience includes the following mandates:
International commercial arbitration – Product liability – Mining equipment
Represents a multinational equipment manufacturer in an international arbitration regarding the performance of equipment sold to a mining company.
Constitutional Law – Division of Legislative Powers – Navigation and Shipping
Represents a Canadian Port Authority and a bulk liquid transhipment terminal operator at first instance and before the Quebec Court of Appeal in a constitutional dispute over the applicability of a provincial environmental protection regime to federal property and to navigation and shipping operations.
Product liability – Industrial, agricultural and construction equipment
Represents manufacturers of industrial, agricultural and construction equipment, as well as contractors, in litigation involving issues regarding the design and performance of various products or works, and the application of legal and contractual warranties.
Telecommunications and Information Technology – Contractual Disputes or Regulatory Compliance
Represents and advises businesses operating in the areas of telecommunications and information technology in contractual disputes, or in connection with the regulatory compliance of their operations.
Professional Liability – Medical Malpractice
Represented physicians and medical clinics in matters involving professional liability, access to information, billing, and disciplinary law.
2014-2019 – Pro Bono Students Canada, Supervising lawyer for the civil law section of the University of Ottawa’s Faculty of Law
2009-2011 – Chairman of the board of directors of Coop Zone (2009-2010) and member of the board of directors (2008 to 2011)
2009-2010 – Harvard National Model United Nations in Boston, Head Delegate, Delegation of the Faculty of Law, Laval University
2009-2010 – Member of the Board of the Student Investment Fund of the Faculty of Law at Laval University
2008-2011 – Member of the Faculty of Law’s Board, Laval University
2006-2007 – Member of the Board of Directors of the Fondation du Cégep de Sainte-Foy
Since 2013 – Young Bar Association of Montreal