Objective: Previous research has consistently demonstrated that religiosity and personal importance of religion are associated with lower levels of alcohol use among both adolescents and college students. Although a number of different mechanisms have been proposed to account for this, few studies have empirically examined potential mediators of this relationship. Given the extensive literature on the impact of social norms on the drinking behavior of college students, the present study evaluates the role of perceived drinking norms as a mediator of the relationship between the importance of religion and alcohol use. Specifically, we examined both personal attitudes and perceived injunctive norms with regard to reference groups that vary in their proximity to students (i.e., close friends and typical college students). Method: Participants were 1,400 undergraduate students (60.6% women) who were assessed using self-report measures of alcohol consumption, importance of religion, attitudes, and perceived norms. Results: Results indicated that, consistent with the hypotheses, personal attitudes were the strongest mediator of the relationship between importance of religion and alcohol use, followed by the approval of close friends, and, to a lesser extent, the approval of typical college students. Conclusions: These findings suggest that importance of religion may have an indirect effect on alcohol use via personal attitudes and the perceived approval or disapproval of important others, and this relationship varies as a function of reference group. Implications for interventions that incorporate information on social norms are discussed.