The present study adopted a multi-informant approach to investigate the contribution of personality and family functioning to moral disengagement and bullying-related behaviors in early adolescence. The sample included 102 early adolescents (53 boys and 49 girls; mean age = 12.21 years; effect size = 0.35, power = 0.95, and error probability = 5%). Behaviors during bullying situations were detected by peer nominations. Self-report measures were administered to assess moral disengagement and family functioning, whereas a parent-report was administered to detect personality traits. Results showed that extraversion was positively associated with bullying and moral disengagement, while benevolence was positively associated with defending behavior. Family functioning was negatively associated with moral disengagement. Furthermore, we found that personality and family functioning were intertwined in their association with bullying-related behaviors and moral disengagement. In particular, a low conscientiousness, together with a low family functioning, decreased the likelihood of defending behavior and increased the risk of bullying. High levels of benevolence decreased outsider behavior in students with a high family functioning. Although extraversion was positively associated with bullying and moral disengagement, findings suggested that it increased moral disengagement only among early adolescents with low family functioning. Overall, findings underline the importance of addressing individual and contextual variables when studying bullying and moral disengagement among early adolescents. Keywords: bullying, defending, outsider,