TMT: Information Technology
France
2 years ranked
LAWYER PROFILE
Jean-Sébastien Mariez
France 2026
Ranked in 1 practice area
About
Provided by Momentum Avocats
France
Practice Areas
Jean-Sébastien Mariez assists key players in the digital economy by protecting their innovation and securing their business activities. His practice focuses on ICT service activities, Media, Gaming, Luxury and Consumer goods. Thanks to his experience as in-house counsel at a large US-based software company and Internet service provider, Jean-Sébastien has an excellent understanding of product lifecycles and business models that he puts to good use as a business oriented advisor and a litigator.
Jean-Sébastien is a contributor to the “Code du Numérique” (Lexis Nexis).
TMT
Information Technology
Intellectual Property
Data Protection
Litigation
Dispute Resolution
Regulatory: Government & Public Affairs (Europe-wide)
Languages Spoken
English
Key sectors
Technology, Media and Telecoms (TMT)Art and EntertainmentHealth and Life Sciences
Chambers Review
Provided by Chambers
Chambers France
TMT: Information Technology - France
Band 3
Individual Editorial
Jean-Sébastien Mariez represents clients in IT and data protection cases. He assists clients with GDPR compliance mandates and the AI Act. He represents IT service providers as well as healthcare and entertainment companies.
Editorial individuel
Jean-Sébastien Mariez représente des clients dans des dossiers d’informatique et de protection des données. Il assiste les clients dans le cadre des mandats de conformité RGPD et à l’AI Act. Il représente des prestataires informatiques ainsi que des entreprises du secteur de la santé et du divertissement.
Strengths
Provided by Chambers
Jean-Sébastien Mariez has specialised knowledge in this area; he knows the law very well, he is very competent, he knows his job very well and the environment in this area of law.
TMT: Information TechnologyChambers FranceIt is a pleasure to collaborate with Jean-Sébastien.
TMT: Information TechnologyChambers FranceI like Jean-Sébastien because he follows policies, he knows public servants and regulators, he is well connected in the tech sector too which is very valuable for us.
TMT: Information TechnologyChambers FranceJean-Sébastien's in-house experience makes the big difference.
TMT: Information TechnologyChambers FranceJ’apprécie Jean-Sébastien parce qu’il suit les politiques, qu’il connaît les fonctionnaires et les organismes de réglementation, et il a un bon réseau dans le secteur IT, ce qui est très précieux.
TMT: Information TechnologyChambers FranceC’est un plaisir de collaborer avec Jean-Sébastien.
TMT: Information TechnologyChambers France
Ranked Individuals at Momentum Avocats (3)
France
Julien Canlorbe
Intellectual Property: Trade Mark & Copyright
View profile Jean-Sébastien Mariez
TMT: Information Technology
View profile 
Julie Carel
TMT: Information Technology
View profile
What success is built on
Chambers is the leading data and intelligence partner for the legal sector.