The study aimed to reveal the leadership role of secondary school principals and its relationship to the level of institutional school excellence. The descriptive correlational approach was used, and the study sample consisted of (180) male and female teachers who were selected from secondary school teachers in the General Administration of Education in Najran region in the south of the Kingdom of Saudi Arabia in the third semester of the academic year 2022/2023. Two questionnaires about the leadership role of secondary school principals and institutional school excellence were used after verifying their validity and reliability. The results indicated that the level of the leadership role of secondary school principals, from the point of view of the study sample, was medium. Also, the level of institutional school excellence in secondary schools from the point of view of the study sample was medium. In addition, the results revealed a positive, direct, and statistically significant correlation between the leadership role of secondary school principals as a whole and its domains and institutional school excellence as a whole and its domains. The study recommended the work of the Ministry of Education to develop a strategic plan for continuous improvement in strengthening the leadership role of secondary school principals and developing institutional school excellence in secondary schools to reach the global level.