LAWYER PROFILE
Marie-Hélène Tonnellier

Marie-Hélène Tonnellier

France 2026

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Ranked in 1 practice area

About

Provided by OYAT

Practice Areas

Marie-Hélène is one of the leading lawyers in the digital world. She advises and litigates on all issues related to IT projects, innovations (AI, robots, etc.), e-commerce and personal data. She also intervenes in media law and intellectual property.

Highly skilled in the sectors of distribution, tourism, luxury, new economy, mobility, media or services, she assists her clients in the implementation of strategic projects or in their digital transformation, helps them navigate through the various new rules in these various fields, assists them in often complex and innovative litigations.

Career

Member of the Paris Bar since 1990, Marie-Hélène co-founded Oyat in 2022.

Marie-Hélène began her career in London within a solicitors’ firm prior to joining Moquet Borde & Associés (Paul Hastings) in 1990, then Jeantet in 1995. Then she has been a partner for 22 years at Latournerie Wolfrom Avocats where she created the digital and intellectual property department.

Professional Memberships

International Federation of Computer Law Associations (IFCLA)

Association Française de Droit de l'Informatique et de la Télécommunication (AFDIT)

International Bar Association (IBA)

ACTIVITIES

Lecturer at the University Paris XI-Saclay, Master Intellectual Property and Digital Law

Lecturer at the HEAD school, Master Digital and Intellectual Property Law

Former President of the IFCLA

Member of the Board of Directors of AFDIT

Member of the International Bar Association (IBA)

Chambers Review

Provided by Chambers

Chambers France

TMT: Information Technology - France

Band 2
Band 2

Individual Editorial

Marie-Hélène Tonnellier advises on a wide range of IT matters, including software agreements, development and integration agreements, and licensing issues. Her clients range from market-leading domestic companies to international brands.

Editorial individuel

Marie-Hélène Tonnellier intervient sur un large éventail de questions informatiques, notamment les contrats de logiciels, les contrats de développement et d’intégration et les questions de licences. Ses clients vont des entreprises nationales leaders du marché aux marques internationales.

Strengths

Provided by Chambers

  • Marie-Hélène is a very reliable adviser, and the quality of her advice is highly appreciated.

    TMT: Information TechnologyChambers France
  • She is an excellent lawyer who listens to the client and is highly appreciated by our team.

    TMT: Information TechnologyChambers France
  • Marie-Hélène Tonnelier has always responded perfectly to our needs, with great responsiveness and availability, demonstrating an excellent ability to analyse cases.

    TMT: Information TechnologyChambers France
  • She is an excellent lawyer with strong market knowledge to advise us.

    TMT: Information TechnologyChambers France
  • C'est une excellente avocate qui est à l'écoute de ses clients et qui est très appréciée par notre équipe.

    TMT: Information TechnologyChambers France
  • Marie-Hélène est une conseillère très fiable, et la qualité de ses conseils est très appréciée.

    TMT: Information TechnologyChambers France

Ranked Individuals at OYAT (4)

France

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