Justice-involved youth experience high rates of adverse childhood experiences (ACEs), placing them in great need of behavioral health treatment and risk for continued justice involvement. Policymakers, government agencies, and professionals working with justice-involved youth have called for trauma-informed juvenile justice reform. Yet, there is currently no available review of the literature on ACEs and their impact on justice-involved youths' psychological, legal, and related (e.g., academic) outcomes to rigorously guide such reform efforts. The current systematic scoping review synthesizes existing literature related to the impact of ACEs on justice-involved youth and offers recommendations for data-driven intervention along the Sequential Intercept Model, which describes five different points of justice system contact (i.e., first arrest, court diversion, detention, and community supervision) in which there is opportunity to intervene and improve youth behavioral health, legal, and associated outcomes. Eight unique studies were included in 40 articles examining ACEs among justice-involved youth; 38% were longitudinal or prospective analyses and none were intervention studies. Studies included delinquency (e.g., recidivism; n = 5), psychiatric (n = 4), substance use (n = 3), and other (n = 2; e.g., academic, pregnancy) outcomes, documenting high prevalence of ACEs and significant associations between ACEs and a variety of outcomes. Implications for clinical services (e.g., targeting youth dysregulation and aggression), agency context (e.g., training police officers in trauma-responsive practices), and system-level changes (e.g., intervening at the time of first ACE documentation such as parent's arrest) are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).