This study investigated how effective school management relates to academic excellence in private secondary schools in Kasaana Sub-County, Uganda. Specifically, it examined the impact of three management practices: strategic resource allocation, adaptive leadership styles, and proactive stakeholder engagement. Using a mixed-methods approach, the research found strong positive correlations between each management dimension and academic performance, with leadership showing the strongest link (r up to 0.815). A regression model indicated that these three factors together explained 74.3% of the variance in academic excellence, confirming their substantial combined influence. All results were statistically significant (p<0.001), leading to the rejection of the null hypotheses. The study concludes that effective school management, built on these three pillars, is crucial for enhancing academic outcomes. Schools that practice transparent budgeting, empowering leadership, and genuine community collaboration achieve better results in national exams, student progression, and critical thinking. It recommends that schools institutionalize transparent budgets, invest in leadership development, and create strong platforms for stakeholder involvement to sustain high academic standards.