This chapter explores the mental health challenges commonly experienced by migrant and refugee children and adolescents, with a focus on the conditions under which migration—especially forced displacement—increases the risk of traumatic and complex traumatic experiences. The developmental and mental health consequences of exposure to adversity across the pre-, peri-, and post-migration phases are discussed. Particular attention is given to the diagnostic complexities posed by trauma-related and culturally mediated symptom presentations. Finally, this chapter outlines therapeutic approaches that can facilitate effective clinical engagement and support the long-term well-being of this vulnerable population.