In recent years, the needs for policy alternatives to reinforce the expertise and leadership of school principals are increasing. This study examines two foreign country’s cases that has already developed and is effectively using professional standards for principals. PSEL 2015 in the United States and APSP 2019 in Australia are selected to systematically investigate the contents of the professional standards for principal. The purpose of this study is to derive implications related to the development of professional standards for principals in Korea. In the United States, the professional standards for principals have focused on student achievement and development. In the case of Australia, leadership requirements and professional practices appear within the leadership context, which shows the overall characteristics that are expected to achieve a high level of learning-professional-school education and talent. Professional standards in the US and Australia had many similarities, including the qualifications and abilities of principals, the purpose of the professional standards, being used as useful standards in the entire process of hiring, selection, training, and evaluation of principals, and providing specific guidelines for action. This implies that it is necessary to develop professional standards for principals that take into account the school situation in Korea in order to improve the professionalism of principals and provide objective standards for appointment and evaluation. The conclusion of this study is that the development and utilization of the professional standards is necessary and very useful for enhancing the principal s professionalism and leadership, and the effectiveness of the school, as seen through two foreign cases. This is because, although the structure and composition of professional standards may differ by country, professional standards functions as practical guideline for improving the professionalism and leadership of the principal.