<p>Previous research on the Big Five personality traits has produced inconsistent findings regarding their role in bullying. This study is the first to use a three-level meta-analysis to investigate the associations between the Big Five personality traits and bullying and victimization among children and adolescents, considering moderators such as mean age, female percent, and type of bullying (traditional vs. cyberbullying). We included 29 studies (67 effect sizes) with 26,328 participants, spanning from 2002 to 2024 across multiple countries. The results showed that conscientiousness and agreeableness were negatively associated with bullying and victimization, while neuroticism was positively associated with both. Openness was unrelated to victimization but negatively associated with bullying. Extraversion was not associated with bullying or victimization. The moderating effects of mean age and female percent were not significant; however, the type of bullying moderated some of these associations. Specifically, victimization in cyberbullying was not significantly associated with extraversion or neuroticism, but in traditional bullying, victimization showed a significant negative association with extraversion and a significant positive association with neuroticism. Regarding bullying, conscientiousness and agreeableness exhibited significantly stronger associations with bullying in traditional bullying compared to cyberbullying. The study also found that publication year did not significantly moderate most of the relationships, indicating that the associations between personality traits and bullying behaviors have remained stable across time. These results could help for the early identification of bullies and victims in children and adolescents to ensure timely interventions.</p>