Deborah is a partner at Thornton Grout Finnigan LLP and an experienced advocate with a broad commercial and civil litigation practice. She acts for individuals, companies and financial institutions providing creative advice and strategies for litigating and resolving complicated business disputes. Her significant mandates include cases involving complex commercial agreements, banking litigation, commercial real estate disputes, fraud claims, shareholder and partnership disputes, insolvency proceedings and securities-related matters over a wide cross-section of industries. She appears regularly in the Ontario Superior Court of Justice and in the negotiation, mediation and private arbitration of commercial disputes. Deborah sat on the Commercial List Users’ Committee (2015-2019), a committee comprised of members of the judiciary, courts administration and senior members of the bar who meet regularly to consider improvements to the organization and operation of the Commercial List.

Deborah is a past President of The Advocates’ Society, the leading association of litigation counsel in Canada dedicated to the promotion of excellence in advocacy, access to justice and a strong, independent and courageous bar. She served on the Society’s board of directors for 8 years (2014-2022) and chaired The Advocates’ Society Task Force overseeing its intervention in the landmark constitutional case Trinity Western University v. Law Society of Upper Canada and Law Society of British Columbia v. Trinity Western University. In 2024, Deborah acted as counsel to an intervenor making submissions on the public interest in fostering a safe environment for discourse and debate at centres of higher learning in University of Toronto (Governing Council) v. Doe et al. She is recognized as a leading litigator in several major legal publications and is a frequent speaker, moderator and advocacy skills trainer.