Green bond issuance has surged in recent years in response to growing investor appetite and borrowers' needs as they embark on the sustainability transition. The EU leads the way, with over 40% of all sustainable bond issuances denominated in euro. The EU's 'Regulation on European Green Bonds and optional disclosures for bonds marketed as environmentally sustainable and sustainability-linked bonds' is the first comprehensive legislative text covering such issuance, and a cornerstone of EU's Sustainable Finance strategy. This book explores in an interdisciplinary way the challenges and opportunities of green bonds and sustainable finance from a legal, regulatory and economic perspectives. First, it analyses green bonds as a new financial instrument in the context of the existing capital markets law. Second, it studies green bond impact on the market and on investor protection. Third, it assesses green bonds' relevance for prudential supervision and central banking. The variety of viewpoints ensures a highly comprehensive analysis of green bonds' impact in a European and global context.