The current study sought to better understand how leisure boredom is associated with alcohol use and how peer factors moderated the relationship between state and trait leisure boredom and past month alcohol use. The 2004 to 2008 multi-cohort study sample included 3,837 high school students (50% female; 91% mixed race; M[subscript age] = 14 years; SD = 0.83) in the Cape Town area of South Africa. Results of generalized multilevel models found peer factors (time spent with peers, injunctive friend norms, descriptive peer norms) and trait, but not state, leisure boredom significantly predicted past month alcohol use. Findings can inform alcohol prevention efforts and suggest both peer factors and trait leisure boredom are worthy targets for intervention. Specifically, supporting adolescents to effectively navigate experiences of leisure boredom may, in turn, reduce alcohol use.