This study is a first-ever attempt to gain a 360° panoramic view of spending in the entire global water sector to better understand the financing and funding gaps in relation to sector goals, and consequently guide thinking on alternative ways to close them. It estimates total water expenditure at various levels of disaggregation, and at the global and regional scales, using several data sources, including budget data and national accounts data, and the updated versions of all available databases on infrastructure spending from various sources, including private and foreign funding. The study thereby presents an integrated assessment of global and regional public spending in the water sector and its main subsectors. It presents findings that seek to answer questions about how public funds are spent in the sector, how well they are spent, and the financing and funding gaps in the sector to help the government meetsector goals. The study is intended as a guide that governments and a range of other stakeholders can use to improve decision-making and thereby facilitate reforms to increase financing and funding in the water sector, enhance the utilization of already allocated funds, and raise the efficiency with which existing resources are employed to maximize development impact.