As schools are becoming more culturally diverse, it is crucial to understand how they can approach this diversity in ways that allow all students to feel included and do well. We focus on the manifestation of two related but distinct approaches to cultural diversity, namely "equality and inclusion" (i.e., promoting positive intergroup contact) and "cultural pluralism" (i.e., embracing students' diverse cultural backgrounds as a resource), in the perceived classroom climate. Specifically, we test a model in which the link of cultural diversity climate at school and student outcomes (achievement, academic self-concept and general life satisfaction) is mediated by sense of school belonging, both at the individual and classroom level. Analyses are based on 1,971 students (61% of immigrant background; M[subscript age] = 11.53, SD[subscript age] = 0.73, 52% male) in 88 culturally diverse classrooms in southwest Germany after their first year at secondary school. Individual- and classroom-level results suggest that both perceived equality and inclusion as well as cultural pluralism are positively associated with outcomes and this link is mediated by school belonging. There were no differences in the effects of (perceived) cultural diversity climate and school belonging between students of immigrant and nonimmigrant background, suggesting that dealing with cultural diversity in a constructive way is beneficial for all students attending multiethnic schools.