Abstract: The article examines the prospects of fiscal and budgetary regulation for sustainable development, focusing on renewable energy as a key driver of ecological transformation. It outlines the theoretical and practical foundations of fiscal mechanisms – including tax incentives, carbon taxation, green funds, targeted financing programs, and public-private partnerships – that promote renewable energy investments in the European Union and Ukraine. The study emphasizes the integration of fiscal discipline, environmental goals, and investment attractiveness within the framework of the European Green Deal. The research highlights Ukraine’s progress in implementing fiscal incentives for solar and wind power, the introduction of guarantees of origin, and the development of digital monitoring systems. The results demonstrate that transparent and predictable fiscal policies are crucial for building investor confidence and ensuring the efficient use of resources. Furthermore, argues that the digitalization of fiscal administration–through artificial intelligence, big data analytics, and integrated information systems enhances accountability and efficiency in managing renewable energy projects. The findings substantiate that the synergy of fiscal regulation, technological innovation, and institutional development forms the basis for Ukraine’s transition toward a low-carbon economy, energy independence, and sustainable growth.