Guillaume Sirois

About Guillaume

Guillaume Sirois is the founder of Elysium Legal. His practice focuses on public law, constitutional advocacy, and tax litigation, drawing on his work as counsel in two national commissions of inquiry and one provincial commission. At the Foreign Interference Commission he cross-examined nearly one hundred witnesses, including the sitting Prime Minister, ministers, and senior officials. He also contributed legal analysis at the Public Order Emergency Commission, examining the police and municipal response during nationwide public order disturbances. Guillaume has litigated claims under the Canadian Charter of Rights and Freedoms and Section 35 of the Constitution Act, 1982 on behalf of vulnerable communities, and he advises businesses on corporate structuring and tax disputes. He clerked at the Federal Court and worked in international human rights with Lawyers Without Borders in Ivory Coast. He earned an LL.B. from the Université de Sherbrooke in 2018 and was called to the Quebec bar in 2020 and the Ontario bar in 2023.

Education & credentials

Law school

Université de Sherbrooke