Cyberbullying has become a critical social issue, which severely threatens children and adolescents’ physical and psychological health. The current research systematically examined the predictors of cyberbullying from the social cognitive and media effects approach. Specifically, this study identified 16 predictors of cyberbullying perpetration and victimization and examined the magnitude of the effects of these predictors by meta-analyzing 81 empirical studies, which represented a total sample of 99,741 participants and yielded 259 independent correlations. The results revealed that risky information and communications technology (ICT) use, moral disengagement, depression, social norms, and traditional bullying perpetration were the main predictors of cyberbullying perpetration, while risky ICT use and traditional bullying victimization were the major contributors of cyberbullying victimization. According to the moderator analyses, country of the sample, sampling method, age, and media platform were significant moderators of the relationships between some specific predictors and cyberbullying perpetration and victimization. Implications for future cyberbullying research were discussed.