Migrant and refugee children face specific challenges that strongly affect their well-being during the integration process in host societies. The institutions and entities in the field dedicated to childhood and migration remark the need to better nuance the factors involved in fostering migrant and refugee children’s well-being, leaning upon researchers to obtain a more accurate portrayal of these childhood experiences. After carrying out a critical narrative review of current models of child well-being and integration, a child-centred analytical frame linking conceptual contributions from both bodies of literature is provided. Upon this basis, a comprehensive theoretical framework that encompasses ecological theory, the new sociology of childhood and interculturalism is discussed thoroughly, with its application in specialised research on this population. These results should be useful for impact policy-making and develop evidence-based psychosocial interventions for migrant and refugee children in Europe.