Background: Health literacy research for adolescents and young people has been growing in importance. However, conceptualisation has been largely limited to concepts of adult health literacy in healthcare and disease prevention settings. The challenge for the future lies in developing a coherent concept that combines adolescent development, educational theory, whole school action and change, and critical health literacy. Such an approach needs to be both enabling and positive for students currently, and should also help facilitate health literacy outcomes in the future. Objective: This paper describes the process used to develop a conceptualisation of adolescent health literacy and to summarise what is known about health literacy in schools. Method: Guided by an international expert panel, we identified, reviewed, summarised and re-constructed key literature and resources to identify key components and principles necessary for adolescent health literacy in schools. Results: The proposed conceptualisation of adolescent health literacy initially had three areas of focus: adolescent development, whole school change and health literacy. The concepts of adolescent learning, health-literate organisation and critical health literacy emerged from the review as key components for health literacy in school settings. Pedagogy was found to be the crucial mechanism for health literacy development in the school setting and the resultant concept of adolescent health literacy. Conclusion: The focus on health-literate organisations, critical health literacy and pedagogy in the school setting distinguishes this conceptualisation from other health literacy work.