Quarantine and isolation represent among the oldest and most fundamental public health tools—separating those who might spread disease from those they might infect. COVID-19 brought these ancient practices into modern daily life, with millions of Canadians experiencing quarantine or isolation requirements. The protocols that govern when and how people are separated from others balance disease control effectiveness against personal liberty, economic disruption, and practical feasibility. Getting quarantine and isolation right matters for both current and future disease outbreaks.