Objective: Exposure to trauma in childhood is associated with an increased risk for internalizing symptoms. Alterations in pubertal development has been proposed as a potential mechanism underpinning this association. However, longitudinal studies, which are needed to examine pubertal development over time, are scarce. The goal of this pre-registered study was to examine how trauma exposure shapes the timing and tempo of pubertal development, and in turn contributes to risk for internalizing symptoms. Methods: Using the largest longitudinal sample to date, we characterized profiles of pubertal development across four time points in female youth from the Adolescent Brain Cognitive Development (ABCD) Study (N = 4,225, age range = 9 to 14 years) using latent class growth analysis. Pubertal development was assessed using the Pubertal Development Scale (at four time-points), trauma exposure was quantified using the post-traumatic stress disorder subscale from the parent-report Kiddie Schedule for Affective Disorders and Schizophrenia for DSM-5 (at baseline), and internalizing symptoms were assessed using the self-report Brief Problem Monitor (at the 3-year follow-up). Structural equation modelling and Kruskal-Wallis tests were leveraged to examine the associations between trauma exposure, pubertal development, and internalizing symptoms.Results: We found that pubertal development could be grouped into three latent classes: early starters (9% of the sample), typical developers (76%), and slow developers (15%). The early starters demonstrated higher levels of trauma exposure compared to typical developers and slow developers, while slow developers reported the least exposure to trauma. Further, youth with greater exposure to trauma were at an increased risk for internalizing symptoms at ages 12–14 years, and this association was mediated by a higher pubertal status at ages 9–10 years, but not by pubertal tempo. Conclusion: Accelerated pubertal development, characterized by an earlier age of onset but not a higher pubertal tempo in the transition from late childhood to early adolescence, may be a mechanism through which trauma exposure in childhood increases risk for internalizing symptoms in female youth.