Purpose: This study examines how public debt influences socio‑economic development and economic competitiveness across the 27 European Union (EU) Member States over the period 2010–2025. Public debt has become a central challenge for fiscal sustainability, shaping countries’ long‑term growth potential, resilience, and the capacity to maintain high living standards. Design/Methodology/Approach: Using Eurostat data, the analysis evaluates the relationship between public debt, GDP per capita, unemployment, and the Human Development Index (HDI), which serves as a synthetic measure of socio‑economic progress. The study applies comparative analysis and regression modelling to assess how differences in public debt levels correspond with disparities in economic performance and competitiveness. Findings: The results show a significant increase in public debt across all EU countries between 2010 and 2025, with the highest levels observed in France, Italy, Spain, Germany, and Belgium. The findings indicate that public debt has a negative impact on GDP growth (coefficient –0.3), while economic growth itself contributes to rising debt levels (coefficient 0.4). The strength of these relationships varies considerably across Member States, with the strongest effects observed in Spain and Ireland. Practical implications: The study concludes that excessive public debt poses risks to fiscal stability and long‑term competitiveness, while moderate debt levels may support socio‑economic development. Originality/value: These results highlight the need for sustainable fiscal governance to ensure balanced growth and resilience in the European Union

Aneta Ejsmont Et Al (2026). Public Debt, Fiscal Stability and Sustainable Competitiveness in the European Union, European Research Studies Journal Volume XXIX Issue 2, 466-484