South Africa’s democratic transition in 1994 marked a historic shift toward constitutional democracy, human rights, accountability, and socio-economic transformation. Despite important democratic gains achieved over the past three decades, the country continues to face serious governance and socio-economic challenges, including corruption, unemployment, crime, weak governance, infrastructure decline, and poor service delivery. These challenges increasingly threaten democratic sustainability, institutional legitimacy, public trust, and national development. The purpose of this study was to critically examine the impact of governance failures and socio-economic instability on the sustainability of constitutional democracy in South Africa. The study was guided by the central problem that persistent corruption, unemployment, crime, institutional decline, and weak governance continue to undermine democratic accountability, socio-economic transformation, and public confidence in state institutions. The study sought to analyse how these interconnected challenges affect democratic governance, social stability, and public trust within the South African context. A qualitative methodological approach was adopted for the study. The research utilised a systematic literature review and document analysis approach to examine existing scholarly literature, government reports, institutional publications, policy documents, and statistical reports relating to governance, democracy, corruption, unemployment, crime, and service delivery in South Africa. Secondary data were obtained from credible national and international institutions, including Statistics South Africa, Auditor-General South Africa, South African Police Service, World Bank, International Monetary Fund, and Transparency International. The key findings of the study revealed that weak governance, corruption, institutional failures, unemployment, poverty, inequality, violent crime, and deteriorating infrastructure continue to undermine democratic accountability and socio-economic development in South Africa. The study further found that corruption and state capture significantly weakened institutional legitimacy and public trust, while unemployment and socio-economic inequality contributed to social instability, crime, and democratic dissatisfaction. In addition, poor service delivery, electricity shortages, failing municipalities, and infrastructure decline emerged as major indicators of governance failure and institutional inefficiency. The findings also demonstrated that democratic sustainability increasingly depends on ethical leadership, institutional reform, accountability, effective governance, and inclusive socio-economic development. The study concludes that although South Africa has achieved significant democratic progress since 1994, the country currently stands at a critical crossroads where governance failures, corruption, socio-economic instability, and institutional decline threaten the long-term sustainability of constitutional democracy. The study recommends strengthening accountability mechanisms, improving governance effectiveness, promoting ethical leadership, professionalising public institutions, combating corruption, enhancing service delivery, and promoting inclusive economic development in order to restore public trust and strengthen democratic stability.