This study examined the association of ringleader bullying with psychopathic traits and theory of mind among 100 youth aged 10–15 (62 boys and 38 girls) receiving inpatient psychiatric services at a state facility. Results of hierarchical multiple regression analyses indicated a positive association between ringleader bullying and psychopathic narcissism, and a significant interaction effect between narcissism and theory of mind. More specifically, narcissism moderated the relationship between theory of mind and ringleader bullying such that theory of mind was positively associated with ringleader bullying when levels of narcissism were high, and theory of mind was negatively associated ringleader bullying when levels of narcissism were low. The discussion of these results focuses on the importance of developing effective treatment techniques for youth whose bullying behavior is associated with narcissistic features and social acuity.