Purpose - Substance use prevalence varies considerably between schools, but to date, whole school approaches for reducing substance use have only been moderately effective. The purpose of this paper is to develop a novel multifaceted whole-school approach to reduce substance use primarily among teenagers aged 11-14 years. Design/methodology/approach - The outlined approach is premised on the proposal that schools can reduce the harms associated with substance use by promoting school connectedness and improving the school-related experiences of weakly connected and disconnected students. The aim of this approach is to develop students' autonomy so that they may act in their real and long-term interests. This may be attained by promoting the realisation of essential human capacities for: practical reasoning-through valued opportunities for cognitive development and affiliation-through valued opportunities for affective development that advance students sense of acceptance within school. Schools may achieve this, it is proposed, by providing outlined forms of appropriate formal support and formal control that are augmented by particular features of school organisation, curriculum and pedagogic practice, which are also described. Findings - A theoretically driven understanding of a whole school approach for reducing teenage substance use is outlined. Originality/value - The outlined approach may usefully inform the development of future whole school interventions aiming to reduce problematic substance use among school students. Additional potential benefits include more successful student life trajectories.