Dennis E. Mahony

About Dennis

Dennis E. Mahony is a partner at Torys who focuses on environmental law, working across regulatory compliance and courtroom advocacy. He leads the firm's Environmental, Health and Safety Practice, co-chairs its Climate Change and Emissions Trading Practice, and holds Law Society of Ontario certification as a specialist in environmental law. He advises a wide range of public- and private-sector clients, including companies, federal agencies, Crown corporations, provincial bodies and municipalities, across nearly every industrial sector, from energy and mining to manufacturing and real estate development. On major projects, he works alongside developers, lenders, consultants and regulators to plan, permit and defend developments, often in sensitive environmental settings, guiding clients from planning through construction and into operation. His advice covers environmental assessments, approvals, stakeholder management and litigation before environmental tribunals and courts. Dennis also helps buyers, sellers, lenders and investors manage the environmental side of transactions, including due diligence, liability assessments and closing details.

Education & credentials

Law school

Faculty of Law