The main objectives of the study were to assess the effect of school management on orphans’ students’ academic performance in Kajiado County, Kenya. The study was guided by the classical organization theory (1930) and the effective school model theory (1989). The study adopted a descriptive survey design, targeting 6 managers, 148 teachers and 5 counselors. The sample was made up of 6 managers, 64 teachers, and 5 counselors. The research instruments used included a questionnaire for managers, teachers and counselors. Qualitative and quantitative data were obtained from the field and data obtained were analyzed by using both descriptive and correlation analysis according to the study objectives. Frequency distributions, percentages, mean scores and Pearson analysis were computed and presented in form of tables. The study found that school planning affects orphans’ academic performance to great extent. Human resource management impacts orphans’ school performance to a great extent and has a positive significant effect on their academic performance. School coordination very greatly influences orphans’ academic performance and also has a positive correlation with academic performance. Evaluation of teachers, teaching methods, and set plans influence orphans’ academic performance to a great extent. The study recommends that specific and orphans-oriented plan should be established in school in order to address academic needs of orphans’ students. Government should help schools and orphanages to develop fundraising systems in order to help orphans’ needs. Schools should also involve qualified volunteers to train managers, teachers and students. The government should improve educational institutions and adoption institutions networks. Key terms: School management, academic performance, orphans