Objective: : We aimed to investigate the mediation of social support in the association between school bullying and suicidal risk among a large group of Chinese children and adolescents. Method: : In this two-wave cross-sectional study, we analyzed 6,063 children and adolescents from southwest China. A two-stage simple random clustering sampling method with probability proportionate to sample size design had been used to select study subjects. Univariate and multivariate Logistic regression models were adopted to determine the inter-associations between school bullying, suicidal risk indicators, and social support. Path models were further fitted to estimate the mediation of social support. Results: : Compared with students who were not involved in school bullying, only victimization was associated with increased suicidal risk, the adjusted ORs for suicidal ideation, suicidal plan, and suicidal attempt were 2.06 (95% CI: 1.61-2.65), 2.07 (95% CI: 1.62-2.64), and 2.41 (95% CI: 1.90-3.05), respectively. Path model indicated that parental social support significantly mediated the association between bullying victimization and suicidal risk. For different types of victimization, only relational bullying victimization was associated with increased suicidal risk, social support from classmates and close friends presented as significant mediators. Limitations: : Causal inference cannot be made because of cross-sectional study design. Information was collected by using self-reporting method, the possibility of information bias exists. Generalization of study results could be limited. Conclusions: : Intervention measures on improving parental and peer social support may be effective in reducing school bullying victimization associated suicidal risk for Chinese children and adolescents.