This is the first review to rigorously examine the mediating role of cognitive factors in the relationship between childhood trauma and subsequent adult psychopathology, and highlight areas for future research. A database search (Child Development & Adolescent Studies, ERIC, Global Health, PsycARTICLES, and PsycINFO) was conducted to identify empirical studies on cognitive factors, explaining the relationship between different types of adverse childhood experiences and adult psychopathology across clinical and nonclinical populations. A narrative synthesis and appraisal of the methodological quality of the studies was conducted. Ninety-eight mediation studies were identified, comprising 4,137 clinical and 28,228 nonclinical participants. Despite great variation in methodological quality of the studies, our narrative synthesis suggests that cognitive factors mediate the relationship between early trauma and later psychopathology. This finding is consistent across different measures of traumatic experiences, psychopathology, and cognitive mediators. Cognitive mediators represent potentially valuable intervention targets for (non)clinical patients who have experienced childhood adversity. Future studies are needed to (a) establish longitudinal causal connections, and (b) assess the effect of interventions that specifically target cognitive change in patients with different levels and types of pathology.