The first prerequisite for taking charge of one’s own health is access to knowledge. Health literacy is a major determinant of population health. It refers to individuals’ motivation and ability to access, understand, evaluate, and use information to make decisions about their health. However, this motivation and these skills depend on the collective—society—which must create favorable educational, societal, and economic conditions. This special report is coordinated by Cécile Allaire (Santé publique France) and Julie Ruel (Université du Québec). Some twenty experts and practitioners in the field contribute their analyses and testimonials.