This study examined the administrative and ethical dimensions of strategic leadership and strategic planning effectiveness and their roles in supporting organizational performance from the perspective of the Ministry of Endowments and Religious Affairs employees. Therefore, the study sought to identify the extent to which officials practice the dimensions of strategic leadership, the effectiveness of strategic planning, and the levels of institutional performance in the ministry. It also examines the impact of the ministry’s strategic leadership and planning effectiveness in supporting organizational performance. To achieve the study's objectives, the researcher used the descriptive analytical method, and the questionnaire was prepared to collect data from the study population represented by employees of the Ministry of Endowments and Religious Affairs in the Sultanate of Oman. The respondents were (513) male and female employees, collected according to the convenient sampling method. The study findings show high levels of employee estimates of both dimensions of strategic leadership (administrative and ethical) and a high level of strategic planning effectiveness. The results also showed a statistically significant effect of strategic leadership practices on organizational performance and a statistically significant impact of effective strategic planning on organizational performance. The study concluded with several recommendations, the most important of which are directing the unit’s officials to work on reviewing the job description and job tasks assigned to employees, working to create new administrative systems through which the ability to develop institutional performance, and working to involve employees in making some decisions and reviewing them by their subordinates before deciding to implement them. Because it has an imprint on the ministry's strategic planning, it has a psychological impact on the employee. Keywords: strategic leadership, strategic planning effectiveness, organizational performance, Ministry of Endowments and Religious Affairs in the Sultanate of Oman