Patrick Duffy

Patrick Duffy

Stikeman Elliott LLP

Recognized since 2019

Toronto, Ontario

Practice Areas

Energy Law

Energy Regulatory Law

Environmental Law

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Patrick Duffy is a partner and Co-Head of the Projects & Infrastructure Group. His practice focuses on project development that includes municipal and planning law, environmental permitting and litigation, energy regulation, and indigenous engagement. He is highly sought after for his considerable experience with environmental assessments and other regulatory approvals in a variety of sectors, including renewable and non-renewable electricity generation, electricity transmission, mining, transit and transportation, aggregate quarries, and waste management. Patrick also advises clients in responding to environmental inspections, investigations and prosecutions at both the provincial and federal levels.

Patrick is an experienced advocate and has appeared before the Supreme Court of Canada, the Federal Court of Canada, all levels of courts in Ontario and a variety of administrative tribunals, including regular appearances before the Ontario Energy Board, the Environmental Review Tribunal and the Local Planning Appeal Tribunal (formerly the Ontario Municipal Board). He has acted for both provincial and municipal governments and many of his cases involve administrative or public law issues.

Patrick is known for his strength in advising on the business interests of energy clients and handling the full gamut of regulatory proceedings in connection with the development of energy projects. He also has expertise in public procurement processes and has been involved in all stages in a number of sectors on both the customer and bidder side. He helps draft the terms of public procurements, assists proponents in responding to procurements, and represents proponents in procurement-related litigation.


  • 5300 Commerce Court West
    199 Bay Street
    Toronto, ON M5L 1B9

Recognized in The Best Lawyers in Canada 2022 for work in:

  • Energy Law
  • Energy Regulatory Law
  • Environmental Law

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