Catherine Gleason-Mercier

Catherine Gleason-Mercier

Associate, Litigation

Contact Information

tel: 416.862.4247



Bar Admission

Ontario, 2013


  • McGill University, LL.B, B.C.L.
  • University of King’s College, B.A. (First Class Honours)


English, French

Catherine is a passionate advocate who provides insightful counsel to clients facing complex legal challenges, particularly in construction and infrastructure disputes, tax disputes and business-critical corporate and commercial disputes. Catherine is dedicated to providing excellent client service and her focused and collaborative approach to achieving client objectives makes her a valued advisor.

Catherine represents a diverse group of clients, including major financial institutions, government entities and multinational public and private corporations. Catherine has represented clients in in the construction and infrastructure industry in a wide array of disputes, including  involving construction liens and trusts, bond and insurance claims, contract interpretation, and delay claims. Catherine also represents large Canadian corporations in tax litigation disputes at all stages of interaction with the Canada Revenue Agency. Catherine has specific experience with disputes regarding transfer pricing and the general anti-avoidance rule.

Catherine has appeared before all levels of court in Ontario, as well as before the Tax Court of Canada. Catherine also has experience with alternative dispute resolution, including mediation and arbitration.

Catherine is deeply committed to access to justice and is a regular Pro Bono Ontario duty counsel volunteer.

    • A Canadian financial institution in its appeals in the Tax Court of Canada involving various excise taxation issues
    • A real estate developer in its defence of a claim for negligent misrepresentation and breach of contract
    • Various public and private generic pharmaceutical companies in various class actions, including in a class action proceeding launched by the B.C. government for opioid related health costs, and in an Ontario class action for Canadian residents arising from opioid use
    • Yogurtworld in its defence of a claim for statutory and common law rescission and breach of the duty of fair dealing
    • Toronto Transit Commission in various court proceedings related to the design and construction of the Toronto York Spadina Subway extension
    • Atomic Energy of Canada Limited in proceedings in connection with the retubing of the Point Lepreau Nuclear Generating Station, as well as proceedings relating to a procurement tendering dispute relating to the refurbishment of a number of nuclear reactors
    • Northland Power in an arbitration respecting a wind and solar power project
    • A Canadian financial institution in in its appeal in the Tax Court of Canada involving issues of deductibility of expenses and transfer pricing
    • A Canadian financial institution in an appeal in the Tax Court of Canada involving issues of transfer pricing and the general anti-avoidance rule
    • Cameco Corporation in connection with an appeal in the Tax Court of Canada involving issues of sham and transfer pricing
    • A Charitable Corporation in connection with litigation arising from the closure of certain camp properties

  • Recipient of the Philip Meyerovitch, Q.C. Prize awarded for the highest standing in Evidence (Civil) (2012)
  • Member of McGill Laskin Moot Team (2011); winners of Overall Team, Best Factum and Second Pair Overall (Appellants)
  • CCAA Academic All-Canadian; ACAA All Conference “Team A” Varsity Women’s Soccer (2006-2008)

  • Amicus at Ontario Court of Appeal
  • Law Help Ontario, Small Claims Court Duty Counsel Volunteer
  • Co-counsel to coalition of professional women soccer players in challenge of FIFA’s use of turf at Women’s World Cup
  • Give a Night in support of HIV/Aids research co-organizer

  • Ontario Bar Association
  • Canadian Bar Association
  • Law Society of Ontario
  • Advocates’ Society
  • Canadian Tax Foundation