This book helps make sense of the emerging and established social innovations that have disrupted and are disrupting the world of finance. Written in an engaging style, this book offers a systematic study of social innovation in the financial services. It introduces the fundamental concepts of financial social innovations (FINSIs), places them in the context of the broader literature, and provides a new framework for understanding and organising these innovations. The book applies the framework to seven existing FINSIs to illustrate their important components and explore their benefits as well as the more negative or harmful aspects to society. These seven FINSIs are microfinance, peer-to-peer (P2P) lending, crowdfunding, mobile banking, impact investing, digital cryptocurrencies, and social impact bonds. The easy-to-follow framework will help to ground the reader’s understanding of FINSIs as the existing ones evolve and new ones are developed. This book is ideal for courses on social innovation, social entrepreneurship, and financial innovation in departments of business, economics, social sciences, and political science.