The present study integrates findings from three lines of research on the association of social cognition and externalizing psychopathology, language and externalizing psychopathology, and social cognition and language functioning using Structural Equation Modeling (SEM). To date these associations have been examined in pairs. A sample of 354 clinic-referred children (aged 7 to14 years) recruited from a children’s mental health centre were tested on measures of language, social cognition, working memory, and child psychopathology. We compared a hypothesized model presenting language functioning as a mediator of the association between social cognition and externalizing psychopathology to a model presenting the independent contribution of language and social cognition to externalizing psychopathology. As hypothesized, we found that the mediation model fits the data better than the alternative model. Our findings have implications for developing and modifying intervention techniques for children with dual language and externalizing psychopathology.