We investigated whether symptoms of attention-deficit/hyperactivity disorder (ADHD) are pathways through which deficits in inhibition and working memory are associated with teacher- and parent-rated social impairment in children. Participants were 64 children (55% males; 53% with ADHD) in grades 3-6. Consistent with our hypotheses, the association between inhibition and social impairment was mediated by hyperactivity/impulsivity and the association between working memory and social impairment was mediated by inattention. Support was not obtained for alternative models wherein the association between inhibition and social impairment was mediated by inattention, and the association between working memory and social impairment was mediated by hyperactivity/impulsivity. Further, tests of hierarchical models suggest that neither inhibition nor working memory is primary but, rather, that these cognitive processes are related to one another and that they collectively (but not uniquely) contribute to hyperactivity/impulsivity and inattention. These findings have implications for conceptual models of ADHD, for understanding factors that influence and sustain social impairment among youth with symptoms of the disorder, and for interventions aimed to addressing such impairment.