In the dynamic and high-stakes realm of the public sector, cost overruns not only disrupt budgets but also hinder project completion. This study aims to identify the critical success factors (CSFs) essential for minimizing such overruns, which are vital for ensuring financial and operational efficiency. Based on a comprehensive analysis of thirty-nine influential factors derived from expert feedback and relevant documentation, the research employed exploratory factor analysis to distill these into five core success factors. Among them, the availability of high-quality databases and resources emerged as pivotal in mitigating excessive costs and enhancing budgetary efficiency. These findings offer a strategic framework for project managers and policymakers, providing actionable insights to optimize cost control and ensure the successful delivery of public sector projects.