<p>Peer defending is effective at reducing bullying interactions and protecting victimised youth, but it is a relatively uncommon bystander response. We investigated correlates of defending to identify ways of promoting these behaviours in schools. Popular students tend to defend at higher rates than others, potentially because of their increased chances of success in these interactions. Defending itself may signal the social dominance of defenders to others. However, aspects of the normative environment in which defending occurs may influence how the behaviour is perceived, which in turn may affect whether students defend at all. Specifically, environments characterised by prosocial norms may promote peer defending, while coercive environments may instead dissuade it. To test this question, we examined the influence of prosocial and coercive norms and gender on the relationship between popularity and defending in early adolescence. A total of 652 students (<i>M</i>_age = 11.94) were recruited from 6 Canadian schools, and data were analysed with multi-level modelling. Results indicated that popularity was positively associated with peer defending. Furthermore, the association between popularity and peer defending decreased for girls as prosocial control norms increased, and the association between popularity and peer defending increased with coercive control norms for both boys and girls. These findings indicate that norms about social power influence the association between popularity and defending for boys and girls in different ways, and that these norms could be configured in schools to promote defending behaviour.</p>