This study examined the influence of strategic planning on resource allocation and effective school management in public secondary schools in Ubungo Municipality, Tanzania. Guided by the Resource-Based View (RBV) Theory, the study employed a mixed-methods approach, integrating quantitative data from 44 teachers and qualitative insights from the head teacher. The sample size was 44 out of a 1000 target population. Questionnaire and interview guides were employed. Validity and reliability were assessed, giving a Correlation coefficient of 0.73. Quantitative data were analyzed using SPSS version 26, while qualitative data were examined thematically. The findings revealed that while strategic planning frameworks are in place in most schools, their practical application in resource allocation remains inconsistent. The report revealed that resource distribution does not align with strategic priorities, least effective, and emphasized the availability of teaching and learning materials as vital for effective school management. Qualitative results highlighted challenges such as delayed government funding, minimal parental contributions, and limited autonomy at the school level, which hinder effective implementation. The study concludes that strategic planning has a positive but constrained influence on school management due to systemic financial and structural barriers. The study recommended strengthening the linkage between planning and budgeting, enhancing monitoring systems, and empowering school leaders through training and autonomy to improve resource efficiency and educational outcomes.