Background: Incarcerated adolescents within the juvenile justice system are more likely to be diagnosed with poor mental health compared with their non-incarcerated peers. Conducting clinical trials on mental health interventions among an incarcerated adolescent population is challenging due to the nature of detention facilities. Objectives: This systematic review examines available literature on Randomized Clinical Trials (RCT) done to assess mental health interventions among incarcerated adolescents globally and to determine the type of intervention that would best work in this setting. In this study, a systematic review was conducted to search, identify, and recommend effective interventions best suited to preserve and improve the mental wellbeing of incarcerated adolescents within the detention institution setting. Method: The search was performed in Medline via Ovid, Cochrane Library, Scopus, and Web of Science databases to retrieve related publications released between 1970 and March 2021. The principal inclusion criteria were RCT articles issued in English that reported any mental health interventions performed in juvenile detention centers involving delinquent adolescents aged 10 to 19 years old. Results: The search discovered 10 related articles that fulfilled the required inclusion criteria. In total, there were seven different types of mental health interventions used in all the studies. The three major themes identified among the selected studies are the interventions for coping strategies, risky behavior, and attention disorder among incarcerated adolescents. The efficacy of the interventions was dependent on the level of intelligence, duration of incarceration, risk of treatment diffusion, and depression symptoms among incarcerated adolescents. Conclusions: Cognitive behavioral therapy (CBT) intervention that is simple, brief, unique, and targets depressive symptoms, has the potential to be most efficacious in improving mental health among incarcerated adolescents.