Research on bullying in Indonesia remains limited, revealing significant gaps in understanding its prevalence and underlying factors specific to the Indonesian context. This study addresses these gaps through a three-pronged approach: (a) assessing the prevalence of poly-bullying victimisation, (b) identifying factors associated with poly-bullying experiences, and (c) evaluating subjective well-being (SWB) in cases of poly-bullying by comparing it with uninvolved children. Cummins' theory of SWB homeostasis was employed to interpret the findings. The study included 10,051 children aged 10 and 12years (50% girls) who reported experiencing poly-bullying in the past month. Data were analysed using descriptive statistics and linear regression. Poly-bullying was measured across five indicators: physical, verbal, and emotional bullying by siblings and other children at school. The analysis considered five independent variables: sociodemographic factors, perceptions of family, friends, and school, and reported fights among students. The results were statistically significant (p<0.000), though the model explained only 5.1% of the variance in poly-bullying victimisation. Poly-bullying was prevalent in both public and non-religious schools. Significant contributors included the frequency of fights among students (β=0.129) and the belief that friends would help (β=0.045). The study's implications for preventing poly-bullying victimisation were also discussed.