The aim of the current study was to investigate the relationship between adolescents' social support, their internalising and externalising behaviour problems, and their alcohol consumption. Adolescents attending Grade 7-10 (N = 329), answered questionnaires regarding their perceived social support (from parents, teachers, classmates, and friends), internalising (emotional and peer problems) and externalising behaviour problems (hyperactivity and conduct problems), and alcohol consumption (monthly frequency of consumption, beverage consumption on the weekend, and problematic consumption). Building a structural equation model, we found negative associations between parent support and all internalising and externalising behaviour problem scales. Furthermore, social support from classmates was negatively associated with the internalising behaviour problem scales. In turn, peer problems were negatively associated with alcohol consumption, and conduct problems were positively associated with alcohol consumption. Both parent and teacher support had a direct effect on alcohol consumption, and parent support also had an indirect effect via behaviour problems. The findings highlight the importance of parents and teachers for alcohol consumption during adolescence.