Research has focused on the role of theory of mind (ToM) for positive social behaviour, while the association between ToM and negative social behaviours is less well understood. This longitudinal study compares two mediation models examining the role of ToM and peer-rated social preference at ages 5 and 6 for bullying at age 7. Participants were 114 children (58 boys, Mage = 67 months) at entry to primary school (T1). At Time 2 (T2), 106 children and, at Time 3 (T3), 96 children remained. Teacher-rated externalizing problems and children’s language ability were controlled at T1. Poor ToM was found to indirectly predict later bullying via poor social preference, while for boys only, greater earlier ToM directly predicted greater bullying 2 years later. These results suggest that there are different pathways to bullying via ToM and social preference, which has implications for interventions to prevent the development of bullying behaviour.