Children and youth are showing increasing levels of mental health distress due to the climate crisis, characterized by feelings of sadness, guilt, changes in sleep and appetite, difficulty concentrating, solastalgia, and disconnection from land. To gain a deeper understanding of the relationship between climate change and children and youth's mental health, we conducted a rapid review and a thematic analysis of the results in NVivo 12. Our findings show that children and youth experience a plethora of direct and indirect effects from climate change and this impacts their mental wellbeing in diverse and complex ways. Young people also have varied perceptions of climate change based on their social locations and many are dealing with feelings of immense worry and eco-anxiety. The mental health impacts of climate change on children/youth are tied to Social Determinants of Health (SDoH) but also need to be understood in relation to the Ecological Determinants of Health (EDoH). Through an eco-social lens, this paper explores these conceptual issues and uses them to provide a framework for understanding the interplay of social and ecological determinants of mental health for children/youth.