This study aimed at identifying the reality of school principals competencies in the management of educational development projects from the perspectives of educational supervisors in the Sultanate of Oman. To achieve the objectives of the study, a descriptive approach was used in order to analyze the literature on professional competencies for school principals, competencies necessary for the management of educational development projects. A questionnaire and individual interviews were designed. The questionnaire consisted of (55) items including five domains: planning, implementation, monitoring, evaluation, team leadership and communication management. The validity and stability of the study tools have been tested. The study sample consisted of (234) male and female educational supervisors, distributed in five directorates of education: (Muscat, Dhofar, Al-Dhakiliyah, Al-Dhahirah, and the South Batinan). The interview was conducted with (10) educational supervisors. The sample was selected random. The statistical data was statistically treated using the SPSS. The study indicated: The estimates of the sample regarding the competencies of school principals in the management of educational development projects according to the five areas of the study were medium, respectively: team leadership, communication management, planning, implementation, and the minimum estimate was for monitoring and evaluation area. - With regard to the variables of the study, it was found that there were no statistically significant differences at level of = 0.05 between the sample due to gender, qualification and work experience variables. There is an agreement between the views of the interview and the questionnaire samples about the reality of school principals competencies in the management of educational development projects, which showed medium estimates in the areas included in the study. In the light of educational development projects literature and the results of the study, the researcher recommended the following: developing the competencies of school principals in managing developmental educational projects through proper training programs. including project management course in the programs of preparation and training of school principals in educational administration. involving school principals in the planning of developmental educational projects at the ministry level.