The Scientific Data Policy regulates the responsibilities and rights of the involved parties with respect to scientific data from public research collected and/or stored by the European XFEL GmbH. It pertains to curation, archiving, and access to scientific data from public research. It also introduces the data management plan. In line with FAIR data principles, this Scientific Data Policy ensures that the scientific data are Findable, Accessible, Interoperable, and Reusable. This version is valid as of 1 January 2025.