Youth involved in the juvenile justice system carry a significant burden of mental health challenges. Internalizing disorders such as depression, anxiety, posttraumatic stress disorder, self-harm, and suicidal behavior are common among justice-involved youth, but often remain overlooked. These conditions influence behavior, increase vulnerability to offending, and heighten the risk of repeated involvement with the juvenile justice system. This review examines the role of internalizing disorders in juvenile offense, and highlights how inward distress can contribute to outward behavioral disturbances. It brings together evidence from multiple countries and shows that untreated internalizing symptoms are linked to higher rates of reoffending, adverse life outcomes, and increased suicide risk. The review also summarizes interventions that address mental health needs among justice-involved youth, including cognitive behavioral therapy, family-based approaches, mindfulness practices, and mentoring models. These interventions show promise for symptom reduction, emotional regulation, and lowering recidivism. The review places special focus on Low- and Middle Income Countries where limited resources, stigma, and gaps in mental health services create major barriers to care.