Background: Developmental language disorder (DLD) has clear functional ramifications in the areas of social competency, emotion recognition, emotional well-being and literacy skill, which have been found to persist from childhood to adolescence. These domains are important factors during the transition from primary to secondary school in typical development (TD). Nevertheless, there is a paucity of research on the transition from primary to secondary school for adolescents with DLD and low language (LL) ability. Aims: To investigate the association between psychosocial domains, literacy skill and concerns about school during the transition to secondary school for adolescents with DLD, LL and their TD peers. The first research question examined whether levels of social competency, emotion recognition, emotional well-being and literacy skill predicted school concern for the three groups. The second research question explored the longitudinal relationship between school concern and psychosocial and literacy indicators over the transition. Methods & Procedures: Participants (aged 10-11 years) with DLD (n = 30), LL ((n = 29) and TD (n = 42) were recruited for this longitudinal study from eight UK primary schools. Standardized language and psychosocial assessments were administered in the spring and summer terms of the final year of primary school, and the autumn and summer terms of the first year in secondary school. Outcomes & Results: Regression analyses showed pre-transition school concern to be predicted by emotion recognition for the DLD group, by social competence and emotional well-being for the LL group, and by social competence for the TD group. Post-transition concern was predicted by emotional well-being for the LL group; with no significant predictors for the DLD/TD groups. Path analyses revealed an association between literacy skill and emotion recognition for the DLD group. A developmental cascade illustrated a relationship between social competence and emotional well-being for the TD group. Conclusions & Implications: This study concludes that transition interventions must be differentiated according to language ability; support for DLD adolescents should focus on emotion recognition skill, provision for LL adolescents should centre on emotional well-being, and TD participants should be particularly supported in the domain of social competence in advance of the move to secondary school. Additionally, this study emphasizes the importance of the inclusion of a LL group, as their outcomes cannot be predicted using DLD/TD research.