Ideologies can legitimate inequality and undermine collective action. Yet research overlooks the effects culture-specific ideologies—ideologies that develop within a specific sociohistorical context—have on collective action support. We address this oversight by arguing that two culture-specific ideologies that deny the contemporary relevance of past injustices (historical negation) and reject Indigenous culture from the nation’s identity (symbolic exclusion) undermine support for collective action on behalf of the disadvantaged (namely, Māori—New Zealand’s Indigenous population). As predicted, historical negation and symbolic exclusion had independent negative cross-lagged effects on collective action support amongst Māori ( N = 561) and New Zealand European ( N = 4,104) participants. The cross-lagged effects of collective action support on historical negation and symbolic exclusion, however, were nonsignificant. Thus, the relationships these culture-specific ideologies have with collective action support are unidirectional. Our results highlight the need to incorporate culture-specific ideologies into models of collective action.