Duncan Macgillivray

Eliot Kolers is the Head of the Litigation & Dispute Resolution Group in the Toronto office, and a member of the firm’s Partnership Board and Executive Committee. Eliot is recognized by his peers as a leading litigator with vast expertise in the areas of corporate commercial litigation, class actions, securities litigation and competition litigation matters. He has represented clients in numerous complex and high-profile commercial cases involving oppression remedies, proxy contests...

Danielle Marks is a top attorney recognized by Best Lawyers in the practice area(s) of Corporate and Commercial Litigation. Danielle, who practices law in Guelph, Ontario, has been recognized since 2026. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Danielle is held by other top lawyers in the same geographic and legal practice area.

Susan D. Mitchell proudly hails from North Bay, Ontario and continues to provide legal services in Northern Ontario as well as Eastern Ontario. Susan works primarily in our Ottawa office, but also travels to our locations in Cornwall, North Bay, and Kingston as needed to meet with clients on personal injury matters. Susan began practicing in 2002 and has been a Partner at Tierney Stauffer LLP since 2007. She became Managing Partner in 2018. Susan practices civil litigation, focusing on person...

When police and other first responders are in trouble, they turn to Eugene Mazzuca. For more than 15 years, Eugene has been the first contact for provincial and municipal entities and their insurers accused of false arrest, excessive force, malicious prosecution, negligent investigation, defamation, personal injury, property damage and other serious torts. He also handles claims against security guards as well as roads liability cases and unusual and novel claims for municipal and provincial ...

Rochelle Perera is a top attorney recognized by Best Lawyers in the practice area(s) of Corporate Law. Rochelle, who practices law in Waterloo, Ontario, has been recognized since 2024. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Rochelle is held by other top lawyers in the same geographic and legal practice area.

Mariam Moktar is a top attorney recognized by Best Lawyers in the practice area(s) of Administrative and Public Law, Corporate and Commercial Litigation and Labour and Employment Law. Mariam, who practices law in Toronto, Ontario, has been recognized since 2025. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Mariam is held by other top lawyers in the same geographic and legal practice area.

Guy Giorno leads the firm’s Political Law practice. He advises clients on lobbyist registration, government accountability and ethics, public-sector conflict of interest and government procurement. Former Chief of Staff to the Prime Minister of Canada, Guy remains an active, influential force in shaping lobbyist registration laws in Canada. Widely recognized as Canada’s leading expert in lobbying law, Guy regularly represents corporate executives and lobbyists in enforcement proce...

As a partner in the Firm, Sarah acts for employers in both the federal and provincial jurisdictions. Her clients operate in a range of industries, including manufacturing, telecommunications, retail, financial services and pharmaceutical. Before joining Filion, Sarah practiced management-side labour and employment law with a global firm. Sarah provides practical and strategic advice to employers on all aspects of labour and employment law. She regularly acts as counsel in wrongful dismissal l...

Cathy serves as the Chief Executive Officer and a partner at OKT. Her practice is focused on advancing Aboriginal and treaty rights through litigation and negotiation. Cathy has represented clients in applications and actions in Ontario and Manitoba, as well as in federal court and at the Supreme Court of Canada. She has also represented Indigenous clients in proceedings and tribunals regarding election processes, labour and employment, and environmental assessment. Cathy provides negotiation...

Lori Mark is a top attorney recognized by Best Lawyers in the practice area(s) of Banking and Finance Law and Real Estate Law. Lori, who practices law in Toronto, Ontario, has been recognized since 2022. This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Lori is held by other top lawyers in the same geographic and legal practice area.