Despite a plethora of research on moral disengagement and antisocial behavior, there is a dearth of literature that explores personality in the context of these undesirable attitudes and behaviors. We provide the first examination of personality, specifically narcissism, as a predictor of moral disengagement and antisocial behavior in sport. Given that narcissism is negatively related to empathy and positively related to feelings of entitlement, it is more likely for narcissists to disengage morally and to behave antisocially. We thus hypothesized that narcissism would predict antisocial behavior via moral disengagement. Across 12 team contact sports (n = 272), bootstrapped mediation analyses confirmed this indirect effect, which remained significant when controlling for motivational climate, social desirability, sex and sport type. Coaches and practitioners would do well to consider the darker side of personality in targeting moral disengagement and its behavioral consequences in team sports.