Men have an important role as allies in reducing discrimination against women. Following the Social Identity Model of Collective Action (SIMCA), we examined whether men's identification with women would predict their allied collective action, alongside moral convictions, efficacy, and anger. We also examined whether identification with their own ingroup would decrease their willingness to improve women's situation. We tested the SIMCA, extended to consider ingroup identification among men, in Japan (N = 103) and the Philippines (N = 131). Consistent with the SIMCA, moral convictions and group efficacy predicted men's willingness to engage in collective action to fight discrimination against women. However, anger was not significant, and identification with the advantaged and disadvantaged groups played different roles in the two countries. We discuss the possible role of norms and legitimacy in society in explaining the pattern of results.