This study aims to provide a new three-way typology of policy legitimacy (i.e., substantive legitimacy, procedural legitimacy, and feasibility-centered legitimacy), while taking into account the relationship between politics (elected officials) and administration (unelected officials) as one of the most significant but under-discussed issues in the studies of policy legitimacy. This analytical framework is used to investigate the empirical case of South Korea's cultural policy. The sequential causal relations between the three types of legitimacy and policy outcomes are then discussed. The case analysis demonstrates that the substantive and procedural legitimacy achieved in the earlier stages of the policy process were not enough to guarantee a successful policy outcome, and hence, feasibility-centered legitimacy was needed as a necessary condition for policy success. If there is a lack of consistency among the three types of legitimacy and coordination issues between elected and unelected officials in the legitimization process, seemingly legitimate policies could have unsuccessful outcomes. This study will contribute to the theoretical advancement of policy legitimacy and to the empirical examination of the legitimization process in recently democratized countries like Korea.