This study critically examines public sector governance in taxation, focusing on the intricate interplay among fiscal accountability, administrative efficiency, and revenue integrity. It investigates how robust governance frameworks enhance transparency in public fund utilization, streamline tax administration processes, and safeguard revenue collection against leakages, corruption, and evasion. Despite growing global emphasis on good governance, a significant research gap persists in integrated empirical analyses that simultaneously address these three pillars within diverse institutional contexts, particularly in emerging economies where fragmented reforms often yield suboptimal outcomes. Employing a mixed-methods approach combining econometric modelling of panel data from multiple jurisdictions, qualitative case studies, and stakeholder surveys, the research reveals that strong fiscal accountability mechanisms significantly boost administrative efficiency, while lapses in revenue integrity erode public trust and fiscal capacity. Key findings demonstrate that digitalization and institutional autonomy improve compliance rates by 18-27%, yet political interference remains a persistent barrier. The implications underscore the urgent need for holistic governance reforms to strengthen state legitimacy, mobilize domestic resources effectively, and advance sustainable development goals through equitable and efficient tax systems.