In this study, we explore how ethnic diversity at the macro-level relates to students’ generalized trust by using cross-national data. Our analysis shows a positive relationship between ethnic diversity and generalized trust. This relationship is, however, inverted U-shaped curvilinear rather than linear, indicating that the positive relationship levels off and turns negative. While we also find that students’ educational experiences such as social relations at school are positively associated with generalized trust, ethnic diversity at the macro-level is still the most powerful factor in our analysis predicting students’ generalized trust. Theoretical and practical implications are discussed.