In recent years technology and sustainability emerged as two main drivers for economy and finance, each with its own characteristics and following independent paths of development. The general discourse on the relationship between technology (more recently financial technology-fintech) and sustainability tended to emphasize the role of technology as a tool for pursuing sustainability mostly from the perspective of financial inclusion. Therefore the relationship with environmental sustainability was less often considered. This book chapter tries to answer the question on the role of digital finance as a tool for pursuing environmental sustainability, and the way specific policies might contribute to pursuing this goal. Adopting this perspective, this book chapter considers the emergence of sustainable digital finance as the clearest result of the interplay between technology and sustainability, assessing its potential for contributing to environmental sustainability. In doing this, this book chapter considers the most relevant public initiatives at the international level and provides a brief overview of the technologies involved in sustainable digital finance, assessing their own specificities and complementarity. Finally, this book chapter makes some critical considerations and proposes some policy suggestions to strengthen sustainable digital finance in a view of achieving ambitious societal goals.