The vast majority of adolescents recognize that bullying is morally wrong, yet bullying remains a problem in secondary schools, indicating young people may disengage from their moral values to engage in bullying. But it is unclear whether the same mechanisms enabling moral disengagement are active for bully/victims (who both bully and are bullied) as for pure bullies (who are not targets of bullying). This study tested the hypotheses that mechanisms of moral disengagement, including blaming the victim and minimizing the impact of bullying, may operate differently in bully/victims compared to pure bullies. From a sample of 1895 students from grades 7-9 (50.6% female; 83.4% from English speaking homes), 1870 provided self-reports on bullying involvement and mechanisms of moral disengagement associated with bullying. Two cut-offs were compared for bullying involvement (as perpetrator and as target of bullying) during the previous school term: a conservative cut-off (every few weeks or more often) and a liberal cut-off (once-or-twice). Using the conservative cut-off, both pure bullies and bully/victims enlisted moral disengagement mechanisms to justify bullying more than did uninvolved students and pure victims, with no significant difference in scores on any of the moral disengagement scales between pure bullies and bully/victims. For the liberal cut-off, bully/victims reported lower overall moral disengagement scores than did pure bullies, and specifically less distortion of consequences, diffusion of responsibility, and euphemistic labeling. This study advances bullying research by extending the role of moral disengagement in bullying episodes beyond pure bullies to victims, both pure victims and bully/victims. Examination of specific moral disengagement mechanisms and the extent of involvement in bullying enabled a more nuanced differentiation between the bullying groups. These results will inform future interventions aimed at reducing the use of moral disengagement mechanisms that sustain bullying and victimization. Targeted interventions are needed to challenge specific moral disengagement mechanisms from the perspectives of pure bullies and bully/victims.