Although scholars have proposed school climate as a key mediator through which school-based management (SBM) can improve educational outcomes, empirical evidence on the relationship between SBM and school climate improvement is sparse. In this article, we use three waves of Programme for International Student Assessment (PISA) data across 57 countries to examine the association between SBM autonomy and different dimensions of school climate (academic, community, and safety). We find that greater school autonomy is associated with significant improvements in all dimensions of school climate, although the strongest improvements occur in safety. Our results show that these improvements primarily occur when schools are given greater autonomy over students (student assessment, admission, and discipline), whereas giving schools greater autonomy over teachers, budgets, or curricula is not associated with climate improvement. Heterogeneity analysis indicates that increased school autonomy is overall associated with improvement in all three dimensions of school climate in high-income countries but not in low- and middle-income countries. However, the positive association between autonomy over students and school climate is observed in both groups of countries. The results suggest that increased autonomy over students should be prioritized in the sequencing of SBM reforms.