Both theoretical and empirical evidence has suggested that childhood maltreatment is positively associated with cyberbullying involvement (perpetration and victimization). However, empirical evidence on the strength of such positive associations is not yet clear. To clarify the strength of the associations, the current meta-analysis examined the extent to which childhood maltreatment is correlated with cyberbullying (perpetration and victimization), and whether these associations varied by sample, publication, and research design characteristics. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a total of 57 studies (N = 98,351 participants) involving 281 effect sizes were included through a systematic literature search of five databases and auxiliary searches. An advanced multilevel meta-analysis approach was employed in R to synthesize the effect sizes. No significant publication bias was found. Results showed that childhood maltreatment was significantly and positively related to both cyberbullying perpetration (mean r = 0.349, p < 0.001) and victimization (mean r = 0.237, p < 0.001). Further, moderator analyses revealed that the association between childhood maltreatment and cyberbullying perpetration was stronger for young adults than for adolescents. Finally, the associations between childhood maltreatment and both cyberbullying perpetration and victimization were stronger for emotional abuse than neglect. The findings suggest that childhood maltreatment is a risk factor for developing both cyberbullying perpetration and victimization. Childhood maltreatment warrants attention in the design of comprehensive prevention and intervention programs for cyberbullying (perpetration and victimization).