Social-emotional comprehension involves encoding, interpreting, and reasoning about social-emotional information, and self-regulating. This study examined the mediating pathways through which social-emotional comprehension and social behaviour are related to academic outcomes in two ethnically and socioeconomically heterogeneous samples totaling 340 elementary-aged children. In both samples, social-emotional comprehension, teacher report of social behaviour, and academic outcomes were measured in a single school year. In both samples, structural equation models showed that the relationship between social-emotional comprehension and reading was mediated by socially skilled behaviour. In one sample, but not the other, the relationship between social-emotional comprehension and math was mediated by socially skilled behaviour. This paper advances our understanding of the mechanisms through which social-emotional factors are associated with academic outcomes.