Catherine DiMarco

Adds value through practical advice and creative solutions.

Catherine DiMarco has more than 17 years of construction and general civil litigation experience.

Certified by the Law Society of Ontario as a specialist in construction law, with a deep understanding of the industry, Catherine provides practical guidance on managing risks during contract negotiations, and assists with project delivery plans.

When disputes arise, she represents different sectors of the construction industry on claims, or on the defence of claims. These include owners, general contractors, subcontractors and suppliers, as well as design and engineering professionals.

Clients appreciate her ability to distill and prioritize key issues and salient facts that arise in complex construction disputes. Her practical and creative approach to dispute resolution is guided by both business drivers and legal remedies.

Catherine has also defended public authorities, including municipalities, in matters involving allegations of negligent design, supervision and inspection.

She regularly attends at the Superior Court of Justice and before arbitrators on a variety of construction and civil matters.

Recognized by the Best Lawyers of Canada™ as a leading lawyer in construction law, Catherine is also a Fellow of the Construction Lawyers’ Society of America. In addition, she is vice-chair and executive member of the Ontario Bar Association Construction and Infrastructure Law Section. Previously, she served as a member of the Executive Committee and Board of Directors of the Canadian Construction Association.

A frequent speaker at industry and client seminars, Catherine has also taught on construction law at the George Brown College School for Architectural Studies and Construction Management and Trades.

She is a volunteer with ProBono Ontario, assisting low-income Ontarians in addressing legal problems that interfere with their ability to lead secure, healthy, and productive lives.


LL.B., Osgoode Hall Law School (2004)
LL.M., Osgoode Hall Law School (2021)
Certificate in Construction Law, Osgoode Hall Law School (2012)
Trinity College Dublin (First Class Hons.) (2004)
Canadian Aviation Institute (Hons.) (1992)

Called to the Ontario Bar, 2005

  • Vice Chair and Executive Member, Ontario Bar Association, Construction and Infrastructure Law Section
  • Past Executive Committee Member and Board Member, and past Vice-Chair, Manufacturers, Suppliers & Services Council, Canadian Construction Association
  • Past Board Member Canadian Association of Women in Construction
  • Past Member at Large, The Advocates’ Society Construction Law Practice Group
  • Member, American Bar Association
  • Member, Women’s Executive Network
  • Member, Toronto Lawyers Association
  • Member, Law Society of Ontario

  • Speaker, Managing Construction Liens in Ontario: Managing Legal Gaps and Conflicts in Contracts and Subcontracts, Osgoode Hall Professional Development Seminar – May 2022

  • Certified by the Law Society of Ontario as a Specialist in Construction Law
  • Fellow, Construction Lawyers’ Society of America
  • Selected by peers for inclusion in Best Lawyers of Canada™ since 2021 in the field of Construction Law
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