A Practice Note providing an overview of Québec's private sector privacy law, the Act respecting personal information in the private sector (CQLR, c. P-39.1), as amended by Law 25, An Act to modernize legislative provisions as regards the protection of personal information (Law 25) (collectively, Québec Act). The Note discusses the Québec Act's application, its data protection principles, and sets out its compliance requirements. This Note also discusses recent Québec Act reform under Law 25 (formerly Bill 64).