Introduction: This systematic literature review provides evidence concerning the association of school race/ethnic composition in mental health outcomes among adolescents (ages 11–17 years). A range of mental health outcomes were assessed (e.g., internalizing behaviors, psychotic symptoms) in order to broadly capture the relationship between school context on mental health and psychological wellbeing.

Methods: A search across six databases from 1990 to 2018 resulted in 13 articles from three countries (United States, United Kingdom, and the Netherlands) that met inclusion criteria following a two step review of titles/abstracts and full-text.

Results: The existing research on school race/ethnic composition and mental health point to two distinct measures of school composition: density—the proportion of one race/ethnic group enrolled in a school, and diversity—an index capturing the range and size of all race/ethnic groups enrolled in a school. Overall, higher same race/ethnic peer density was associated with better mental health for all adolescents. In contrast, there was no overall strong evidence of mental health advantage in schools with increased diversity.

Conclusions: Theoretical and methodological considerations for future research towards strengthening causal inference, and implications for policies and practices concerning the mental health of adolescent-aged students are discussed.