Background: Mindfulness-based interventions (MBIs) are increasingly used in the management of various mental health disorders in children and adolescents. However, there is limited evidence about the efficacy of various interventions used. Method: A systematic review was performed to examine the effects of different MBIs on mental health symptoms and quality of life in both clinical and nonclinical samples of children and adolescents using data from only randomized control trials. The studies were also assessed for quality. Based on the type of MBI, study population, and control arm we had three comparisons for meta-analyses. Results: Fifteen studies were included in the qualitative analysis but only 11 trials with comparable interventions and controls were included for meta-analyses. Mindfulness-based stress reduction/mindfulness-based cognitive therapy arm was more effective than nonactive control in the nonclinical populations. Acceptance commitment therapy was comparable to active treatments in patients in the clinical range. Other MBIs were also effective improving anxiety and stress but not depression in nonclinical populations compared to nonactive control. Conclusions: Mindfulness-based interventions can be effective in children and adolescents with mental health symptoms. As there were significant limitations these results must be interpreted with caution.