Research suggests that many children are exposed to adverse experiences in childhood. Such adverse childhood exposures may result in stress and trauma, which are associated with increased morbidity and mortality into adulthood. In general populations and trauma-exposed adults, mindfulness interventions have demonstrated reduced depression and anxiety, reduced trauma-related symptoms, enhanced coping and mood, and improved quality of life. Studies in children and youth also demonstrate that mindfulness interventions improve mental, behavioural, and physical outcomes. Taken together, this research suggests that high-quality, structured mindfulness instruction may mitigate the negative effects of stress and trauma related to adverse childhood exposures, improving short- and long-term outcomes, and potentially reducing poor health outcomes in adulthood. Future work is needed to optimize implementation of youth-based mindfulness programs and to study long-term outcomes into adulthood.