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William Deneault-Rouillard, Associate

William Deneault-Rouillard

Associate Fasken
Jurisdiction Québec, 2019
Language(s) French, English
Office(s) Montréal


William’s practice includes a focus on commercial law, data governance, privacy, cybersecurity and online marketing. He assists emerging tech companies and data-driven businesses with legal risk management and contractual negotiations, and advises them on the operationalization of concepts such as privacy by design in a wide range of industries, including software-as-a-service (SaaS), big data, FinTech, EdTech, MedTech, the Internet of Things (IoT), artificial intelligence (AI), neurotechnology and blockchain.

William is known for his ability to provide creative solutions adapted to clients’ strategic and business objectives. The companies he assists range from start-up and emerging companies to Fortune 100 and 500 companies.

With a background as a M&A corporate lawyer, William frequently drafts and negotiates various types of commercial contracts, including SaaS and data processing agreements. He also advises clients on consumer protection requirements applicable to e-commerce and digital services. Upon multijurisdictional data breaches, William assists clients during the whole incident response and remediation process to mitigate the risks of exposure and subsequent litigation. Recognized by its clients and its peers for its versatility, he also provides regulatory advice on all issues related to the Charter of the French Language, product labelling and advertising.

Engaged in the business community and within his peers, he acts since 2020 as a lawyer in residence for the Canadian Chamber of Commerce (Innovation and Digital Economy Committees), as vice-president of the Tech Law Committee of the Young Bar of Montreal, and is a member of the board of directors of the Young Leaders Circle of the International Economic Forum of the Americas.


Client Work

  • Clearspring Capital Partners and OneLink Capital invest in Groupe Tecnic and École de conduite Tecnic Rive-Nord alongside one of the founding families,
  • Wavin B.V. acquires Bow Plumbing Group Inc., a leading Montreal-based manufacturer of plastic pipes and fittings,
  • Champlain Financial Corporation acquires Armoires Cuisines Action,
  • Arthur J. Gallagher & Co. acquires PCI-Perrault Conseils Inc.,
  • GrowthCurve Capital acquires a majority interest in Montreal-based leading play-to-earn and game discovery platform,
  • Coveo Solutions Inc. closes $215 million initial public offering and concurrent private placement,
  • Advent International acquires leading specialty chemicals solutions provider Caldic from Goldman Sachs Asset Management, Ongoing since November 2021
  • Merger of AGA Benefit Solutions and WBL Benefits and Actuarial,
  • Walter Global Asset Management, in partnership with Bonnefield Financial’s management team, on its acquisition of Bonnefield Financial,

Career & Education


  • LLM, Information Technology Law Université de Montréal
  • LLB Université Laval
  • Certificate, Business Administration Université de Sherbrooke

Memberships & Affiliations

  • Lawyer in residence, Canadian Chamber of Commerce (Innovation and Digital Economy committees)
  • Vice-president, Technology committee of the Young Bar of Montreal
  • Member of the Board of Directors, Circle of Young Leaders of the International Economic Forum of the Americas
  • Member – St. Lawrence Consortium


Fasken Institute


Article, Co-Author Reopening digitalized economy : Practical privacy, cybersecurity considerations The Lawyer's Daily

Speaking Engagements


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