Little is known about the role of active school travel (AST) on mental health among adolescents. Thus, this study aimed to explore the AST-depression association among adolescents aged 12-15 years from 26 low-and middleincome countries (LMICs). Data from the Global School-based Student Health Survey were analyzed in 51,702 adolescents [mean (SD) age 13.8 (1.0) years; 49.3% boys). Both depressive symptoms and AST were assessed by a single question self-reported measure, respectively. Participants who reported having 5 days or above were considered as AST. Multivariable logistic regression analysis (accounting for sampling weights) was performed while controlling for gender, age, physical activity, sedentary behavior, and food insecurity, and a countrywide meta-analysis was undertaken. The prevalence of depressive symptoms and AST were 30.1% and 37.0%, respectively. Compared with those not having AST, adolescents with AST were less likely to have self-reported depressive symptoms (OR = 0.88, 95%CI: 0.85-0.93) regardless of gender. Countrywide meta-analysis demonstrated that having AST versus not having AST was associated with 12% lower odds for depressive symptoms (OR = 0.88; 95%CI: 0.82-0.94) but with a moderate between-country heterogeneity (I 2 = 59.0%). Based on large samples of adolescents from LMICs, it would be expected that AST may play a critical role in preventing adolescent depression worldwide. However, it is necessary to consider more country-specific This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.