Jean-Simon Schoenholz is a versatile litigator with a bilingual, national practice focusing on public law strategy, appellate advocacy, and commercial litigation. Jean-Simon regularly appears before the federal courts and the Supreme Court of Canada, including in high-profile and high-stakes matters. In doing so, he brings to bear his perspective as a former judicial law clerk in both courts. Jean-Simon also acts before all levels of court in Ontario and is licensed in Québec.

Jean-Simon is regularly engaged when clients are affected by government and government agency decisions, including to challenge government regulation. He also acts for public institutions, including Crown corporations, airport and port authorities, and universities, where their decisions are challenged. As part of his public law practice, Jean-Simon is regularly called upon to advise clients on complex matters of statutory and regulatory interpretation. This notably includes lending support to clients engaged in government consultations and as part of broader government relations strategy. He also advises Crown corporations on governance matters. Jean-Simon has unique experience participating in high-profile public inquiries, most notably as commission counsel to the Emergencies Act inquiry.  He has been ranked "One to Watch" in public and administrative law since 2022.

Jean-Simon is one of a small group of lawyers who regularly act for federal institutions with respect to their obligations under the Official Languages Act. He regularly assists them in responding to investigations by the Commissioner of Official Languages, improving compliance, and representing them in the federal courts to respond to claims for damages.

Jean-Simon is the firm's Supreme Court of Canada Agent. He is also chair of the Canadian Bar Association's Supreme Court Liaison Subcommittee. Jean-Simon is regularly called upon to represent clients on appeals in a wide range of industries and subject matters, including commercial, insurance, employment and labour, and public law. He has successfully obtained leave to appeal and leave to intervene before the Supreme Court of Canada.

Jean-Simon is very involved in the firm and the legal community. He is a member of the Ottawa Student Committee. He sits on the executive of a number of Canadian Bar Association sections, including the national Administrative Law section. He teaches Administrative Law and Civil Procedure. In 2022, he co-coached the University of Ottawa's team in the Laskin Moot (administrative and constitutional law) to a third place finish. Jean-Simon regularly volunteers with Pro Bono Ontario's Supreme Court Leave Application Assistance Program.