Purpose <p>Peer victimisation, often a serious childhood stressor, has been associated with poor cognitive outcomes. The current study sought to uncover whether peer victimisation is associated with poor cognitive functioning in childhood via inflammation.</p> Methods <p>Data from 4583 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) were analysed. Path analysis was conducted to determine whether inflammation, measured using IL-6 and CRP levels (age 9), mediates the effects of peer victimisation (age 8), even after controlling for other stressors, on multiple cognitive outcomes, including working memory (age 10), reading (accuracy, speed, and comprehension) (age 9), spelling (age 9), response inhibition (age 10), attentional control (age 11), and selective attention (age 11).</p> Results <p>IL-6 and CRP partially mediated the effects of peer victimisation on working memory, reading accuracy, and selective attention. IL-6 partially mediated the effect of peer victimisation on reading comprehension, while CRP partially mediated the effect of peer victimisation on reading speed. All effects were small. Inflammation did not mediate the effects of peer victimisation on spelling, response inhibition or attentional control.</p> Conclusion <p>Peer victimisation may impact on some aspects of children’s cognitive functioning via inflammation. The cognitive outcome specificity observed warrants further research.</p>