Unfortunately, the role of school leadership in fostering school improvement in non-Western countries, especially African countries, is relatively little discussed. The present study sheds light on the contextual role of instructional leadership (IL) and transformational leadership (TL) in promoting the Ethiopian School Improvement Program (SIP), which is intended to enhance student academic performance. Hence, this study aimed to extend the integrated leadership model by conceptualizing the moderating mediation effect of IL on student academic achievement in public primary schools. A cross-sectional study was performed by distributing a survey to 1280 public primary school teachers in Addis Ababa. Surprisingly, the study’s findings affirmed that unlike previous studies, IL and TL significantly directly affect student academic performance, and TL plays a significant role as a moderator of the indirect effect of IL on student academic achievement.