This study empirically investigates how nationality diversity of top management team in MNCs' headquarters affects foreign subsidiary's CEO localization. Hypotheses are derived both from upper echelons perspective and social identity perspective on the localization of subsidiary CEO. Using a sample of 84 Korean wholly owned subsidiaries of 66 S&P 500 American MNCs from 2000 to 2014, panel logistic regression analysis and Cox survival analysis have been conducted. The panel logistic results shows that nationality diversity of HQ TMT has a positive relationship with localization of CEOs of foreign subsidiaries. This means that the greater the nationality diversity of the top executives in the headquarters, the more likelihood to staffing host country nationals as subsidiary CEOs. Cox survival analysis reports that nationality diversity of HQ TMT has positive relationship with proportional hazards of subsidiary CEO localization. This demonstrates that as the nationality of HQ TMT diversify, the propensity of subsidiary CEO succession from PCNs to HCNs increase. It also found that local experience of foreign subsidiary positively moderates the impact of HQ TMT’s nationality diversity on subsidiary CEO’s localization. This study provides academic and managerial implications as follow. In the theoretical aspect, this study presented the nationality diversity of the headquarters' top management as a determinant of the localization of CEOs of overseas subsidiaries. Applying upper echelons theory and social identity theory, the study explains the impact of the nationality diversity of the top executives of the headquarters on the localization of CEOs of foreign subsidiaries. In the managerial aspect, the international human resource management and the ability to manage multicultural organizations are crucial for the successful implementation of global strategies by multinational corporations. In order to strengthen the global capabilities of MNCs, this study suggests that internationalization of nationality composition of headquarters' top management as well as the localization of manpower of foreign subsidiaries is important.