LAWYER PROFILE
Dennis E Mahony

Dennis E Mahony

Global 2026

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Ranked in 1 practice area

About

Provided by Torys LLP

Global

Practice Areas

A leading lawyer in his field, Dennis has specialized knowledge in environmental law. From regulatory compliance to courtroom advocacy, Dennis works closely with clients on bespoke tactics to mitigate risk and maximize opportunity in environmental matters impacting clients’ operations, projects and transactions.

Dennis is the head of Torys’ Environmental, Health and Safety Practice, the Co-Chair of the firm’s interdisciplinary Climate Change and Emissions Trading Practice and is certified by the Law Society of Ontario as a Specialist in Environmental Law.

Dennis provides comprehensive environmental, health and safety advice to a broad range of public- and private-sector clients, including public and private companies, federal government agencies, Crown corporations, provincial bodies and municipalities.

On projects, Dennis works alongside developers, lenders, technical consultants, regulators and other project stakeholders to plan, develop, permit and defend complex projects, often through sensitive environmental habitats. He regularly advises from the project planning stage through the approval and construction stages and into operation.

Dennis also assists buyers, sellers, lenders and investors through all environmental aspects of a transaction: from acquisition diligence and agreement negotiation, to the design and coordination of deal-specific environmental liability assessments, negotiation of agreements and in handling closing and post-closing details.

Chambers Review

Provided by Chambers

Chambers Global Guide

Environment - Canada

Band 1
Band 1

Individual Editorial

Dennis Mahony is an esteemed lawyer who handles the full spectrum of issues in the environmental space, including environmental approvals for major energy and transportation projects and permitting matters, as well as associated litigation. He is based in Toronto.

Strengths

Provided by Chambers

  • Dennis provides exceptional service with strong technical skills and practical awareness.

    EnvironmentChambers Global Guide
  • We have no need to go anywhere else - Dennis puts everything on autopilot for us.

    EnvironmentChambers Global Guide
  • Dennis is, by far, the best environmental lawyer with whom I have had the privilege to work with. He looks beyond the narrow question of a specific legal point to see the big picture.

    EnvironmentChambers Global Guide
  • Dennis is very proactive and forthcoming. He provides very sound advice.

    EnvironmentChambers Global Guide

Ranked Individuals at Torys LLP (80)

Canada

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