OBJECTIVE: The aim of this study was to investigate both implicit and explicit drinker identity as mediators of reward sensitivity and problematic drinking. University students engage in problematic levels of alcohol consumption, exposing them to increased negative health outcomes. Although personality traits (e.g. reward sensitivity) and social-cognitive variables (e.g. implicit and explicit drinker identity) have been used to investigate drinking behaviour, few studies link personality and multiple indices of drinker identity to problematic drinking. DESIGN: University students (N = 136) completed a drinker identity implicit association test, and questionnaires measuring reward sensitivity, explicit binge drinker identity and problematic drinking as part of a lab-based correlational study. MAIN OUTCOME MEASURES: The Alcohol Use Disorders Identification Test was the main outcome measure with participants self-reporting drinking frequency, quantity and negative physical and psychological outcomes of drinking over the past 3-months. RESULTS: A mediation model revealed that reward sensitivity was significantly associated with explicit, but not implicit, binge drinker identity. Explicit binge drinker identity mediated the reward sensitivity and problematic drinking association. CONCLUSION: This research provides an evidence base for identity-based drinking interventions for students characterised by high reward sensitivity, by promoting identities that do not idealise problematic drinking behaviour.