About Rousseau Mazzuca LLP

Rousseau Mazzuca LLP is headquartered in downtown Toronto, with a second office in Peterborough. Its team of about fifteen lawyers covers four areas: construction law, employment and labour law, commercial and corporate law, and litigation. The firm describes itself as serving Toronto, the GTA, and the rest of Ontario with 40+ years of experience, and its clients range from large and small businesses to trade unions and individual clients.

Aaron Rousseau is a founding partner of the firm. Rousseau began at a Bay Street firm, then moved to a specialized employment law firm before founding Rousseau Mazzuca, and has since appeared before labour arbitrators, the Ontario Human Rights Tribunal, and the Ontario Labour Relations Board. Michael Mazzuca earned a Master of Laws from Osgoode Hall Law School, a postgraduate diploma in legal studies from the College of Law in Sydney, and a Bachelor of Laws from Melbourne Law School. Mazzuca has been a teacher and lecturer of law courses at the university level and has published on construction and employment law. The firm belongs to the Toronto Construction Association.

Milestones & recognition

  • Aaron Rousseau is listed in Best Lawyers in Canada for Labour and Employment Law.
  • Michael Mazzuca is listed in Best Lawyers in Canada for Construction Law.
  • A lawyer at the firm is a Law Society of Ontario Certified Specialist in Corporate and Commercial Law.
  • Michael Mazzuca played professional hockey in the Ontario Hockey League for the London Knights and Kitchener Rangers, and later captained Melbourne Ice in the Australian Ice Hockey League, before practicing law; Mazzuca now advises on and litigates matters involving sport violence, harassment, discrimination, and sport administration.

In the community

  • The firm is a member of the Toronto Construction Association.

Good to know

A person using a wheelchairWheelchair accessible

This firm’s lawyers at a glance

Law schools
University of British Columbia, University of Western Ontario 2 of 15 lawyers

The neighbourhood

The firm's Toronto office is in the Thomson Building at 65 Queen Street West, a 24 storey tower built in 1970 on the southwest corner of Queen and Bay, in the middle of the city's financial core. The building connects directly into the PATH and the subway, and it sits across from Toronto's present and former City Halls, a stretch of downtown built for banking, government, and legal work.

Frequently asked questions

I think I was let go unfairly. Can Rousseau Mazzuca help?
Yes. The firm's employment and labour team represents employees in wrongful dismissal, constructive dismissal, and severance negotiations, along with claims involving human rights, harassment, and unpaid wages or commission.
We're an employer dealing with a difficult termination or a workplace policy problem. Does the firm work with businesses too?
Yes. Rousseau Mazzuca also acts for employers, drafting and reviewing employment contracts and workplace policies, handling misconduct and discipline matters, and defending discrimination and human rights claims.
I'm in a payment or lien dispute on a construction project. Does the firm handle that?
Construction law is one of the firm's core practice areas. Its lawyers review, draft, and negotiate construction contracts, including CCDC and EPC agreements, and act on construction lien and other project disputes, as well as Occupational Health and Safety Act charges.
I want to incorporate my sole proprietorship. Can Rousseau Mazzuca help?
Yes. The commercial and corporate group handles incorporations for sole shareholders and more complex multi shareholder structures, along with ongoing corporate filings, commercial agreements, and business purchase and sale transactions.
I'm a landlord, tenant, or buyer in a dispute over a property. Can the firm represent me?
The litigation team acts for buyers, sellers, landlords, tenants, and owners in real estate disputes, including mortgage foreclosures, liens, renovation defects, and evictions, before Ontario's courts and tribunals.
Where is Rousseau Mazzuca located?
The firm is headquartered at 65 Queen Street West in downtown Toronto and has a second office in Peterborough.

Where to find them

Toronto, Ontario, M5H 2M5 · 416-304-9899

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Listing compiled from the firm’s public website in August 2026. Verify licence status in the Law Society of Ontario directory ↗