Cognitive distortions are an important focus in many investigations and treatments of externalizing problem behavior, such as antisocial, delinquent, and aggressive behavior. Yet the overall strength of the association between cognitive distortions and externalizing behavior is unknown. Furthermore, it is unknown whether interventions can effectively reduce cognitive distortions and subsequently externalizing behavior. To fill these gaps, we conducted a meta-analysis of 71 studies on 20,685 participants. Results showed a medium to large effect size (d = .70) for the association between cognitive distortions and externalizing behavior. Interventions had a small effect (d = .27) on reducing cognitive distortions. In a subset of intervention studies that incorporated both cognitive distortions and externalizing behavior, however, neither cognitive distortions nor externalizing behavior were effectively reduced. Hence, although cognitive distortions are substantially linked to externalizing behavior and interventions can reduce cognitive distortions, a subsequent reduction in externalizing behavior remains to be demonstrated.