Bullying involvement may have an adverse effect on children’s educational outcomes, particularly academic achievement. However, the underlying mechanisms and factors behind this association are not well-understood. Previous meta-analyses have not investigated mediation factors between bullying and academic achievement. This meta-analysis examines the mediation effect of cognitive-motivational factors on the relationship between peer victimization and academic achievement. A systematic search was performed using specific search terms and search engines to identify relevant studies that were selected according to specific criteria resulting in 11 studies encompassing a sample total of 257,247 children (10 years and younger) and adolescents (11 years and older) (48–59% female). Some studies were longitudinal and some cross sectional and the assessment for each factor was performed by various methods (self, peer, teacher, school and mixed reports). Children involved in bullying behaviour were less likely to be academically engaged (k = 4) (OR = .571, 95% CI [.43, .77], p = .000), to be less motivated (k = 7) (OR = .82, 95% CI [.69, .97], p=.021), to have lower self-esteem (k = 1) (OR = .12, 95% CI [.07, .20], p=.000) and lower academic achievement (k=14) (OR = .62, 95% CI [.49, .79], p = .000). Bullying involvement was also significantly related to overall cognitive-motivational factors (k=17, OR= .67, 95%CI [.59, .76], p=.000). Cognitive-motivational factors, taken together, mediated the association between bullying victimisation and academic achievement (k = 7,OR = 0.74, 95% CI (0.72, 0.77), p = 0.000). Bullying victimisation was negatively related to cognitive-motivational factors, which, in turn, was associated with poorer academic achievement. These findings were moderated by the design of the studies, assessment methods for the bullying reports, mediators and outcomes, country, age of children in the sample and/or types of bullying. The findings are of relevance for practitioners, parents, and schools, and can be used to guide bullying interventions. Interventions should focus on improving internal and external motivational factors including components of positive reinforcement, encouragement, and programs for enhancing academic engagement and achievement amongst children and adolescents.