Héléna Gagné

Héléna is a partner in the Tax law group at the Montreal office, and co-leads the national Private Client practice. Her practice primarily focuses on tax, estate planning, as well as taxation of high-net-worth individuals, Wills and Estate and Trust Law. During her career in leading law firms in Montréal, Héléna has developed strong relationships with high-net-worth individuals and private clients for whom she provides personalized tax and estate planning advice.

Héléna also counsels individuals, families, trustees of trusts, liquidators/executors, and family offices on all aspects of estate planning, estate administration, and wealth transfer planning. She works with a wide variety of domestic and international clients to address their planning needs and possesses significant experience with closely-held family businesses and the multi-generational families that own and control these businesses. 

Héléna is a member of the Society of Trust and Estate Practitioners and is internationally recognized as a Trust and Estate Practitioner (TEP). She has also taught law courses at the Master of Laws (Taxation) at HEC Montréal, and regularly gives lectures on the topics of tax and estate planning and trust law.

Representative Work

  • Advised company founder in post-liquidity event wealth transfer planning.
  • Advised trustees of trusts with ownership stake in major family business on all tax and family business matters.
  • Advised liquidators/executors in post-mortem tax planning.
  • Advised trustees of trust in connection with reorganization and eventual termination of trust.
  • Advised trustees of trust in connection with the 21-year rule deemed disposition.
  • Reorganized capital structure of operating businesses of family-owned company in conjunction with wealth transfer planning.

Latest Insights

  • Webinar Apr 4, 2023

    2023 Budget Briefing: Key Updates and Proposals

    Watch members of Osler’s Tax practice group for an informative webinar discussion of recent legislative amendments and proposals included in the...

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    2023 Budget Briefing: Key Updates and Proposals
  • Osler Update Nov 29, 2022

    British Columbia announces plan for retroactive legislation to confirm B.C. PST will not apply to federal luxury tax

    Late last week, British Columbia announced its intention to introduce retroactive legislation to confirm that its provincial sales tax will not apply...

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    British Columbia announces plan for retroactive legislation to confirm B.C. PST will not apply to federal luxury tax
  • Osler Update Mar 28, 2022

    Draft select luxury items tax legislation released

    On March 11, 2022, the federal government released draft legislation to implement a select luxury items tax (Luxury Tax). The Luxury Tax was...

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Media Mentions

  • 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...

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  • Osler News Jan 26, 2022

    Héléna Gagné joins Osler’s National Tax Group in Montréal

    Osler is pleased to welcome Héléna Gagné as a partner in our Tax Group working out of our Montréal office.

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Community Involvement

  • Tax and Financial Planning Association, Organizing Committee Colloquium on Trusts
  • CHU Sainte-Justine Foundation, Member of the organizing committee – Urban Duathlon
  • Young Canadians in Finance, Board Member, Past President of the Executive Committee
  • STEP Canada, Executive Council Member
  • Estate Planning Council of Canada, Member

Speaking and Writing

Speaking Engagements

speaker 26/11/2023
Canadian Tax Foundation 75th Annual Conference
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speaker 04/4/2023
2023 Budget Briefing: Key Updates and Proposals
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speaker 18/10/2022
Tax Planning for Entrepreneurs and Founders – Toronto
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l’Association de planification fiscale et financière (APFF) symposium
Panelist, February 16, 2023

Colloque sur les fiducies de l’APFF
Speaker, Common pitfalls and best practices in setting up a discretionary family trust in the context of an estate freeze with Jean-Philippe Dionne, Montréal, March 2022

Midi-conférence de l’APFF
Speaker, Tax on Split Income from A to Z: Rules, Exceptions and Interpretations, Québec, March 2022

Congrès annuel de l’Association de planification fiscale et financière (APFF)
Speaker, Étude des règles de l’impôt sur le revenu fractionné et application à un cas pratique évolutif, October 2021

Colloque sur les Fiducies de l’APFF
Speaker, Les 21 ans de la fiducie – Avec dévolution irrévocable, February 2020

Colloque sur les Fiducies de l’APFF
Speaker, Les considérations pratiques de la dévolution testamentaire au conjoint/à une fiducie exclusive au conjoin, February 2020

Congrès national de SFL
Speaker, Tax : Planification post-mortem et sujets d’actualité en fiscalité successorale, September 2019

National Estate Planning & Trusts Conference
Speaker, Trust Amendments – Common Law and Civil Law – What Every Tax Lawyer Needs to Know, Canadian Tax Foundation, May 2019

Young Canadians in Finance Breakfast Conference
Moderator, Venture Capital with Magaly Charboneau from Inovia Capital, April 2019

Lunch-meeting of the Canadian Bar Association
Speaker, Implications fiscales en présence de non-résidents dans le contexte de planifications successorales, April 2019

Déjeuner-causerie de la CCI française au Canada
Speaker, Comment organiser son patrimoine dans un contexte international : avoir les bons réflexes, March 2019

Colloque sur les Fiducies de l’APFF
Speaker, Revue de la jurisprudence fiscale en matière de fiducies, February 2019

Midi-conférence de l’APFF
Speaker, Démystifier l’acte de fiducie et certaines des clauses essentielles dans le cadre de planifications fiscales et successorales, February 2019

Published Work

  • « Investissement Boeckh inc. c. Agence du revenu du Québec », Canadian Tax Foundation, Vol 23, No. 3, July 2023 (with Marc Roy and Yanni Stavrakis).
  • « Mony: TCC Reiterates Abusiveness of Half-Loaf Planning », Tax for the Owner-Manager, Vol. 23. No 1, January 2023 (with Evan Belfer and Caroline Berthelet).
  • « Significant changes to Quebec’s Charter of the French Language could impact estates and trusts », STEP Inside, Vol 21, No. 3, November 2022 (with Alexandre Fallon).
  • “Interest Deductibility in Canada: The TDL Group Co. Decisions”, Tax Notes International, May 2016.
  • “Interest Deductibility in Canada: What’s the Fuss?”, Tax Notes International, July 2015.



  • HEC Montréal, LL.M. Fisc.
  • University of Montréal, LL.B.


  • English
  • French

Professional Affiliations

  • Barreau du Québec
  • Estate Planning Council of Canada
  • STEP Canada, member of the Executive Board
  • Young Canadians in Finance, member of the Board of Directors
  • Society of Trust and Estate Practitioners
  • Association de planification fiscale et financière (APFF)
  • Canadian Tax Foundation (CTF)