This study investigated the relationship between deviant peer affiliation, impulsivity and online gaming addiction in adolescence, and explored the moderating role of impulsivity in the relationship between deviant peer affiliation and adolescents’ online gaming addiction. Questionnaires were given to 1813 adolescents. The results indicated that: (1) both deviant peer affiliation and impulsivity positively predict online gaming addiction in adolescence after the sex and age were controlled; (2) the relationship between deviant peer affiliation and adolescents’ online gaming addiction was moderated by impulsivity, that is, the positive association between deviant peer affiliation and online gaming addiction was stronger for adolescents with high as compared to low impulsivity.