The Earth Observation for high impact multi-hazards science (EO4Multihazards) is a two-year project launched as part of the joint European Space Agency-European Commission Earth System Science Initiative. The project is dedicated to bolstering preparedness for high-impact multi-hazard events through the utilization of Earth Observation technologies for enhanced forecasting, risk quantification, and vulnerability assessment. These objectives are in line with the calls from existing literature stressing the pivotal role of data and information in effective disaster risk management, as well as the importance of establishing a collective and accessible database. Through a series of workshops, the project provides a platform for diverse scientific contributions from various disciplines, fostering collaboration and knowledge exchange among experts. The project aims to bridge the gap between the scientific and user-driven domains by integrating so-called science and demonstration cases. These cases inform the scientific process with real-world experiences but also ensure the inclusion of local contexts in scientific endeavours. The science cases are introduced to showcase different spatial scales, geographical locations, socioeconomic characteristics and a range of hazards and their interrelated effects. They will focus on distinct geographical regions characterized by a variety of events, including hot, dry, and wet conditions, and will examine different types of hazard interactions. In a subsequent phase, the demonstration cases will augment this assessment by incorporating data on exposure and vulnerability, thereby expanding the multi-hazard assessment into a comprehensive multi-risk assessment.