This research examined the association of national identity with system justification and collective action against economic inequality specifically relating to socioeconomic status (Study 1), ethnicity (Study 2) and gender (Study 3) among both disadvantaged and advantaged groups. Additionally, in Study 3, we investigated the competing predictive role of national narcissism. Across all studies ( N  = 3387) and regardless of group membership, we consistently found that participants who scored higher on national identity showed stronger system justification and, in turn, lower joint collective action intentions. After controlling for national narcissism in Study 3, however, the relation of national identity with joint collective action through system justification became non‐significant. Instead, national narcissism was positively related to system justification and then negatively associated with joint collective action after controlling for national identity. These results advance the understanding of the psychosocial pathways that undermine collective efforts towards social change, thereby contributing to the maintenance of economic inequality.