Gerald Grenon

Gerald is a partner in the firm’s taxation practice. His practice encompasses all stages of tax dispute resolution from dealing with CRA audits to litigating in court.

Gerald has appeared before the Tax Court of Canada, Federal Court of Appeal, Supreme Court of Canada and Alberta Court of Queen’s Bench, including such well-known cases as Canada Trustco v. The Queen (the first Supreme Court of Canada decision on the General Anti-Avoidance rule in which a taxpayer was successful), Shell Canada v. The Queen (where the Supreme Court of Canada held that: the Crown was not allowed to tax on substance over form; interest deduction allowed; gain on hedge capital) and 3850625 Canada Inc (formerly Fording Coal) v. The Queen (where the Federal Court of Appeal held that refund interest increased the taxpayer’s resource allowance deduction).

Prior to joining Osler, Hoskin & Harcourt LLP, Gerald was a partner with a leading Calgary firm and its affiliated firm, KPMG Canada, practising in the area of tax dispute resolution and litigation. Before commencing his practice as a tax litigator, Gerald served as a Judicial Clerk to the Honourable Barry Strayer of the Federal Court of Appeal.

Awards and Recognition

  • The Canadian Legal Lexpert Directory: Recognized in Litigation – Corporate Tax; Corporate Tax
  • The Lexpert Guide to the Leading US/Canada Cross-border Litigation Lawyers in Canada: Recognized in Litigation – Corporate Tax; Canada corporate tax litigation lawyers
  • Best Lawyers in Canada: Recognized in Tax Law
  • International Tax Review: Recognized in Tax Controversy as a Highly Regarded Lawyer
  • Who’s Who Legal: Recognized in Corporate Tax – Controversy; Canada – Corporate Tax

Media Mentions

  • Osler News Nov 23, 2023

    23 Osler lawyers recognized in Lexpert Special Edition: Litigation 2023

    23 Osler lawyers featured in the Lexpert Special Edition: Litigation 2023.

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  • Osler News Aug 25, 2023

    Osler recognized as a Tier 1 firm in ITR’s World Tax Guide 2024

    Osler is proud to once again be recognized as a Tier 1 firm in the 2024 edition of the International Tax Review’s World Tax guide. Additionally, 19 of...

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  • Osler News Apr 19, 2023

    42 Osler lawyers recognized by Lexpert as leaders in Finance and M&A

    Osler is proud to announce 42 of our lawyers have been recognized as leaders in the Lexpert Special Edition: Finance and M&A 2023.

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  • Osler News Oct 4, 2021

    Osler recognized as a Tier 1 firm in ITR’s World Tax Guide 2022

    Osler has maintained its Tier 1 rankings in ITR’s World Tax Guide with 18 lawyers recognized as leaders in their field.

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Speaking and Writing

Published Work

  • Gerald has authored and co-authored numerous articles on income tax matters, and is a frequent speaker, including presentations at the annual conferences of the Canadian Tax Foundation and the Canadian Petroleum Tax Society.
  • Gerald has also served as a Lecturer to the CICA’s Corporate reorganizations course respecting the topics of the General Anti-Avoidance rule and interest deductibility.



  • University of Manitoba (LL.B.)
  • University of Manitoba, B.A. (History)


  • English

Professional Affiliations

  • Canadian Petroleum Tax Society, Member and Former Director
  • Canadian Tax Foundation, Member
  • Canadian Bar Association, Member