Water resources management (WRM) is a key global challenge. Water is essential to life through drinking water and sanitation and is fundamental to the provision of food, energy, and health. Extremes of the water cycle (floods and droughts) can have tremendous impacts on all human activities, especially for vulnerable populations. Water is therefore of central importance to development and has been recognized as one of the United Nations Sustainable Development Goals. The exponential growth of satellite based information over the past decade provides unprecedented opportunities to support and improve WRM. Furthermore, traditional barriers to the access and usage of satellite data are lowering as technological innovations provide opportunities to manage and deliver this wealth of information to a wider audience. Satellite remote sensing is thus increasingly being used as a complementary source of information to in situ monitoring networks and, in many cases, is the only feasible source. Satellite‐based sensors are now capable of making direct and indirect measurements of nearly all components of the hydrological cycle. These include precipitation, evaporation, lake and river levels, surface water, soil moisture, snow, and total water storage. These sensors are therefore capable of providing critical information in support of managing water and monitoring the evolution of hazards and their impacts. Although some of these satellite remote sensing products are in their infancy and although there are limitations, the large spatial coverage and high temporal resolution mean that they can provide near‐global information in near real time. We review the state‐of‐the‐art for relevant variables, current satellite missions, and products, how they can be used to assess and monitor water resources. This will be exemplified by actual uses of Earth observation satellite products for agricultural water management, for support services to the provision of input for basin-wide water resources information systems, as well as for flood risks management (understanding disaster risk in all its dimensions of vulnerability, exposure of persons and assets, hazard characteristics, enhancing disaster preparedness, strengthening emergency response, contributing to disaster risk reduction by improving resilience).