Societies in many parts of the world either become increasingly culturally, ethnically, and linguistically diverse (e.g., in many European countries) or have a longer tradition of dealing with diversity (e.g., in the U.S.), driven by either more recent or earlier waves and types of migration or settlements (e.g., Gabaccia, 2019). Despite these different contextual conditions, all these societies include groups of people, such as migrants, immigrants, ethnicities, races, or members of different religions, that share the experience of being a cultural minority . Children and youth of cultural minorities may be confronted with stereotypes, prejudices and exclusion and are therefore at greater risk for lower well-being, mental health, and academic achievement (Dimitrova et al., 2016). Following a risk and resilience perspective (Motti-Stefanidi & Masten, 2013), however, they also have unique strengths and can do well if protective factors are in place. Schools can provide such a protective and supportive environment to which children and youth have (almost) universal access. How schools respond to the challenges and opportunities arising with cultural diversity thus has profound implications for individual students’ well-being and life paths, as well as for the economic and social well-being of all members of society (OECD, 2018). However, schools and classes differ with regard to how cultural diversity is approached, and in how these different approaches are reflected in the respective school or class climate (e.g., Schachner, 2019; Verkuyten & Thijs 2013). For the purpose of the current work, we subsume these different approaches under the umbrella term “diversity school or classroom climate”. We define “diversity school or class climate” in terms of (a) the practices and policies implemented in, communicated about, and negotiated within schools and classes as well as the beliefs, values, and attitudes that shape interactions between students and between students and teachers, and the prevailing tone and atmosphere in schools or classrooms (see e.g., Bardach et al., 2020; Wang & Degol, 2016). These practices and policies (b) represent manifestations of approaches to dealing with cultural diversity in school settings, such as valuing different backgrounds and cultural diversity, equal treatment of all students etc. (e.g., Schachner et al., 2021; Verkuyten & Thijs, 2002; Byrd, 2017). To date, scholars have coined and used a multitude of terms and concepts to describe different elements of a diversity climate. However, to the best of our knowledge, a systematic overview of conceptualizations and operationalizations of diversity climate approaches and a discussion of their overlap, similarities and differences is currently lacking. Moreover, different diversity climate approaches have been linked to a number of important student outcome variables. For instance, in several studies, diversity climate approaches have been shown to be related to academic achievement, sense of belonging, and/or motivational beliefs of students with an immigrant background as well as their native peers (e.g., Bayram Özdemir & Özdemir, 2020; Baysu et al., 2021; Oczlon et al., 2021). Nonetheless, although review and overview papers focusing on associations between cultural diversity approaches and student outcomes exist, they have either focused on selected diversity approaches (e.g., Okoye-Johnson, 2011), were restricted to one world region, and/or did not conduct a systematic literature search (e.g., Schachner, 2019), which makes it likely that not all relevant work was covered. In light of these gaps, we will conduct a systematic review of current school-based research on diversity climate. The following three research questions will be addressed: (1) Which conceptualizations and measures have researchers used to describe different diversity climate approaches in school settings? (2) What similarities and differences between different conceptualizations and measures exist? (3) What are the main findings regarding effects of diversity climate approaches on student outcomes (or at least relations between diversity climate approaches and student outcomes)? What additional findings (e.g., findings from mediator/moderator analyses) have been reported that can contribute to a more comprehensive understanding of the connection between diversity climate and student outcomes?