Digital entrepreneurship has emerged as a key driver of innovation, economic development, and sustainable business growth in India. The rapid adoption of digital technologies, including artificial intelligence, cloud computing, big data analytics, blockchain, e-commerce, digital payment systems, and social media platforms, has significantly transformed the entrepreneurial ecosystem. Simultaneously, business sustainability has become a strategic priority for start-ups seeking long-term competitive advantage while balancing economic, social, and environmental responsibilities. Despite India's position as one of the world's largest start-up ecosystems, many digital ventures continue to face challenges related to resource constraints, technological disruptions, cybersecurity risks, regulatory compliance, and sustainable growth. This study investigates the relationship between digital entrepreneurship and business sustainability among Indian start-ups. A quantitative research design was employed using a structured questionnaire administered to 300 founders, co-founders, and senior managers of recognised start-ups operating in major entrepreneurial hubs across India. Data were analysed using descriptive statistics, reliability analysis, Pearson correlation, multiple regression analysis, and one-way ANOVA through SPSS. The findings reveal that digital entrepreneurship positively and significantly influences business sustainability by enhancing innovation capability, operational efficiency, customer engagement, organisational resilience, and competitive advantage. Digital innovation emerged as the strongest predictor of sustainable business performance. The study concludes that effective integration of digital technologies enables Indian start-ups to achieve long-term sustainability while contributing to national economic growth. The findings provide valuable implications for entrepreneurs, investors, policymakers, and researchers in strengthening India's sustainable digital entrepreneurial ecosystem.