Objectives: To enhance clinical and multicentre research outcomes in systemic lupus erythematosus (SLE), standardised documentation of patient- and disease-related features is important. The aim of this European Alliance of Associations for Rheumatology (EULAR) taskforce was to define a core set of essential items for the comprehensive care of SLE patients in clinical practice, with an extension for vital elements required for translational and observational research. Methods: A multidisciplinary EULAR task force group engaged in a multistep approach including a 4-round Delphi survey and a face-to-face meeting. Results: Twenty-five stakeholders from 14 different countries participated. During the process, the initial list of 99 items was reduced to 73 items for inclusion in the clinical core dataset and 8 additional items for research extension. The items were grouped in the domains ‘general’, ‘disease activity’, ‘disease history’, ‘disease damage’, ‘comorbidities’, ‘patient reported outcomes’, ‘laboratory markers’, ‘outcomes’, and ‘treatment’, with suggested frequencies of assessment. Conclusions: The presented clinical core dataset and its research extension are designed to improve SLE patient care and facilitate collaborative research by ensuring the comparability of datasets and cohort descriptions. This initiative lays the foundation for the establishment of a global SLE data space and has the potential to expedite the implementation of personalised medicine in SLE care.