Website: millerthomson.com
Head office address (Canada): Scotia Plaza, 40 King Street West, Suite 6600, Toronto, ON M5H 3S1
Year established: 1957
Ownership structure: private Canadian law firm partnership
Target market/client profile: corporations, employers, plan sponsors, and public and private sector organizations seeking business law and labour and employment legal counsel
Number of professional staff: around 500 lawyers; more than 1,300 total staff
Canadian office locations: Toronto (head office), Vancouver, Calgary, Edmonton, Saskatoon, Regina, London, Waterloo Region, Vaughan, Montréal
Miller Thomson LLP is a Canadian law firm with around 500 lawyers spread across 10 offices in five provinces. The firm covers a broad range of practice areas, with pensions and benefits, labour and employment, and corporate law among its core offerings. It also serves clients in both English and French through its national office network.
Miller Thomson LLP started in 1957 as a six-lawyer practice called Miller, Thomson, Hicks & Sedgwick. The founding team worked out of 55 Yonge Street in Toronto, close to the city’s financial core.
Over the decades that followed, the firm went through two distinct growth periods. Each one added offices, lawyers, and practice depth in new parts of the country.
The first growth period came through the 1960s as the Toronto office steadily added lawyers and broadened its work. Corporate and commercial mandates formed the core of that expansion.
By the early 1990s, the firm had a strong enough base to pursue something bigger. That platform became the starting point for a more deliberate push throughout Canada.
Between 1992 and 2007, Miller Thomson LLP grew through a series of mergers with established regional practices. In 1999, Cook Duke Cox, an Edmonton firm with roots in Alberta’s post-oil-rush era, joined the fold.
The following year, a merger with Swinton & Company, a Vancouver practice founded in 1951, brought Miller Thomson into British Columbia. In 2005, the firm moved into Quebec through a merger with Pouliot Mercure, a Montréal commercial law firm founded in 1952.
In 2011, the firm merged with Balfour Moss, a Saskatchewan practice with roots going back to 1895, and opened offices in both Regina and Saskatoon. A Vaughan, Ontario office followed in 2017 as part of a broader Greater Toronto Area expansion. In July 2025, Enzo Di Iorio, the managing partner who built the Vaughan office from the ground up, became the firm’s Chair.
Miller Thomson LLP offers legal services across multiple practice areas, including pensions and benefits and labour and employment:
The firm’s private equity group also advises large pension funds on structuring investments and transactions. Its health law group serves insurers, health service providers, and regional health authorities.
Enzo Di Iorio serves as Chair of Miller Thomson LLP and practices in commercial disputes and construction law. Ontario courts at all levels have seen him as counsel, and several legal publications have noted his work in that area. Di Iorio holds an LLB from Osgoode Hall Law School and completed Harvard Business School’s Executive Education program in 2025.
Di Iorio leads Miller Thomson LLP alongside its Executive Committee:
The firm’s business operations are led by:
The Executive Committee oversees the firm’s strategic direction, governance, and partnership operations. It also guides national growth, talent development, and client service standards.
Miller Thomson LLP works with clients across the public and private sectors, including:
The firm’s pensions and benefits group advises plan sponsors, pension administrators, and employers on governance, funding, and member matters. Its labour and employment group covers collective bargaining, disability management, and pay equity compliance. The private equity group also works with large pension funds on investment structuring and transactions.
Miller Thomson LLP covers 34 industry sectors, with particular depth in:
For international matters, the firm works through Multilaw, connecting clients to member firms in more than 100 countries.
Plan sponsors and administrators can find Miller Thomson LLP’s full contact details in our Benefits and Pensions Monitor legal directory.
Miller Thomson LLP has received recognition from legal and business organizations, with active community and industry involvement:
The firm also runs a formal pro bono program covering duty counsel services, university legal clinics, and community agency support.
Lisa Goodfellow, a partner in the labour and employment group, spoke to BPM in January 2026 about sick leave reforms and AI disclosure requirements in hiring. Her comments covered Ontario’s new rules on AI screening tools and the broader push across provinces to ease sick note requirements.
Employers juggle rising wage floors, longer sick leave and stricter hiring disclosure rules
