Our theoretical approach has two pillars, which have also guided the empirical design. First: Integration is a multidimensional process where structural, cultural, social and psychological aspects are intertwined. Second, integration can be fruitfully understood as an intersection between origins (O), destinations (D), and exposure (E). The project covers eight themes, centred around questions derived from the international literature and from our knowledge about the specific contexts we study. The themes concern, e.g., the role of exposure to the destination country, gendered patterns of integration, the prominence of a Muslim/non-Muslim divide, selective acculturation, and how ethnic inequalities are patterned by educational tracking/streaming. With our multidimensional approach, we seek to move the research landscape away from fragmentation and towards a more holistic perspective on integration. Our themes look at patterns of, and interactions between, (1) structural integration, e.g., youth’s educational and economic situation, (2) social integration, e.g., friendship across ethnic lines, but also exclusion and bullying, (3) cultural integration, e.g., values, identity and religiosity, and (4) psychological adaptation, e.g., mental wellbeing and anti-social behavior. Our research will respond to pressing contemporary questions where systematic knowledge is missing, thereby providing important input to evidence-based policy-making.