Achieving sustainable development requires investment in an inclusive, green economy. Today, mismatches between what is financed and what needs financing contributes to continued environ¬mental deterioration of natural capital and insufficient investment in infrastruc¬ture and people to secure inclusive prosperity. Financial decision-making responds to price and policy signals in the real econo¬my, but is also impacted by how the financial system is organized, informed par¬ticularly by the actions of the financial system’s governing institutions, including government ministries, central banks and regulators, and rating agencies, stan¬dard setters and stock exchanges. The UNEP Inquiry has explored how changes in financial system design can bring the environment more effectively into financial decision-making. Its insights have been informed by an international Advisory Council and insights from practical country experience and extensive international engagement and research reflected in over fifty research papers. The Inquiry’s insights suggest an historic opportunity in shaping a financial sys¬tem that can more effectively finance the development of an inclusive, green economy. Such an opportunity can be achieved through leadership commit¬ted to developing the financial system to ensure it meets its broader purpose through complementary and coordinated action by financing institutions, those governing the system, and policymakers. The Inquiry’s Three Key Messages Are That: Financing for sustainable development can be delivered through action within the financial system, as well as in the real economy. Policy innovations from developing and developed countries demonstrate how the financial system can be better aligned with sustainable development. Systematic national action can now be taken to shape a sustainable financial system, complemented by international cooperation.