["European Journal of Social Psychology, EarlyView. ", "\nABSTRACT\nPrevious research has focused on disadvantaged groups seeking social change, overlooking how dominant groups mobilize to preserve the status quo. Across three studies (two correlational, one experimental), we explored how collective grievance—the feeling of being or having been collectively wronged by an outgroup—drives system‐preserving collective actions and aggressive intergroup tendencies. Additionally, we examined whether conservative orientations moderate and dehumanization mediates these effects. Study 1 found that grievance was linked to outgroup dehumanization, non‐normative collective action intentions and aggressive inclinations more than other predictors, such as identity fusion and moral convictions. Studies 2 and 3 revealed that collective grievance increased outgroup dehumanization, strengthening non‐normative collective action dispositions and aggressive tendencies, but only among conservative individuals. This research highlights how majority group members, particularly with conservative ideologies, can be motivated by collective grievances to mobilize in defence of the status quo and exhibit aggressive intentions towards outgroups through their dehumanization.\n"]