The present study investigated how students' attitudes toward bullying were influenced simultaneously by personal and contextual factors in Mainland China, Hong Kong, and Taipei. Participants included 25,338 students (15-year-olds, from grade 7 to 12) and 663 schools from Mainland China, Hong Kong, and Taipei drawn from the Program for International Student Assessment 2018. Multilevel structural equation modeling with Bayesian estimation was conducted for data analysis. The results showed that, for personal factors, girls had stronger anti-bullying attitudes than boys in each sample. Resilience and self-efficacy predicted students' anti-bullying attitudes positively and significantly in all three regions. For family contextual factors, parents' emotional support had positive effects on students' attitudes toward bullying in three regions. For school contextual factors, there was no consistent result among the three regions. School location and school belonging were positive predictors of students' anti-bullying attitudes in Mainland China. By contrast, class size and student behavior hindering learning negatively correlated with students' anti-bullying attitudes in Hong Kong. In Taipei, students in public schools were more likely to form anti-bullying attitudes, and a positive association was found between the student--teacher ratio and students' attitudes toward bullying. Distinguishing the commonalities and differences in the factors influencing students' attitudes toward bullying in Mainland China, Hong Kong, and Taipei provides empirical evidence to understand school bullying prevention and control mechanism.