This book explores the potential for public banks to help finance the expansion, democratization, and sustainability of public water services in Europe, with implications for public water financing elsewhere in the world. Financing the UN’s Sustainable Development Goal 6 for water and sanitation will be enormously expensive and will also depend largely on public water operators. Where will this money to fund public water services come from? One option is public banks. These state-owned institutions constitute just under 20% of global banking assets, holding close to $50 trillion in assets. Many public banks have explicit mandates to finance public water management and related public goods, and they have been doing so for decades. And yet, despite a resurgence of interest in public banks, their roles and potential in funding public water services have been largely ignored by researchers and policy makers. This book aims to measure the scale and nature of interactions between public banks and public water operators in the European region; identify challenges and opportunities for deeper engagement between public banks and public water operators; recognize promising practices and how these might be transferred elsewhere in the world; and assess possibilities for more democratic forms of public bank and public water interactions. This volume will be of great use to students and researchers interested in political ecology and economy, development and cooperation, public policy as well as water governance and management. The chapters in this book were originally published as a special issue of Water International.