This study investigates the impact of the Treasury Single Account (TSA) on government accountability within public sector organizations in South-South Nigeria. The research specifically examines how TSA influences two key indicators of accountability: tracking surveys and financial reporting quality, and further explores the moderating role of Political Will. A quantitative research design was adopted, with data collected through structured questionnaires distributed to 286 personnel across selected public organizations. A total of 261 valid responses were analyzed using SPSS version 27, with regression and multivariate analysis employed to test the hypotheses. The results indicate that TSA has a significant and positive effect on both tracking surveys (β = 0.985, p < 0.001) and financial reporting quality (β = 0.982, p < 0.001), demonstrating TSA's effectiveness in improving transparency, traceability, and timely reporting in government finance. Furthermore, the introduction of Political Will as a moderating variable significantly enhanced the relationship between TSA and government accountability (β = 0.389, p < 0.001), confirming that leadership commitment plays a vital role in the success of financial management reforms. The study concludes that TSA significantly contributes to strengthening accountability mechanisms in public sector organizations and recommends that the government sustain strong political commitment to TSA implementation and enhance monitoring mechanisms for compliance. These findings provide empirical support for the continued institutionalization of TSA as a critical tool for public financial management and reform in Nigeria.