The current study examined associations between proactive and reactive aggression and disciplinary actions in an academic year among middle school-age youth at Time 1 (Fall) and 6-month later (Spring) and evaluated school attachment as a moderator of these links. Findings indicated that reactive, not proactive, aggression was robustly positively associated with disciplinary actions in both Fall and Spring. School attachment was negatively associated with disciplinary action in both Fall and Spring but did not moderate the links between either function of aggression and disciplinary actions at either time point. Findings suggest that reactive, not proactive, aggression is linked with disciplinary actions at school, and this effect is independent of levels of school attachment. Implications for these findings are discussed.