Deliverable 9.1 for the WorldFAIR Project’s Biodiversity Work Package (WP09). Biodiversity standards are essential for FAIR data, in particular for interoperability. Current standards need to be improved with new data models to better reflect the complexity of biodiversity and serve the information needed to address biodiversity loss and climate change. This Deliverable D9.1, focused on Task 9.1, describes the FAIR data model being developed in WorldFAIR WP09 with the Global Biodiversity Information Facility (GBIF) leading a community collaboration. Facilitated by the WorldFAIR project, GBIF’s engagement with the biodiversity community has led to this Deliverable – a new draft core Unified Model. The model was developed in collaboration with the Biodiversity Information Standards Group (TDWG) and through community consultation via webinars, open drafting of documents and solicitation of test datasets from the various stakeholders. A review of comparable standards has led to the development of a draft core model framework that is known to the community which should make adoption easier. The new model is centred around the ‘Event’ – something happened at some place during some period of time, optimally described by a protocol. This conclusion is based on research which describes how successful models are expressed and the flexibility of the Event to accommodate many types of data. The Unified Model is applicable to all currently-used data types and potential new data to be shared with GBIF. The current community engagement approach (more on which in D9.2) is to test individual components of the model with engagement activities and example datasets. This will continue with new tests expanding the potential utility of the model. The WP tasks performed to date (collation of previous material, engagement with TDWG and Darwin Core (DwC) standard leads, webinars, use of shared documents to build use cases, building of exemplar datasets for collection management systems, and provision of several avenues for feedback) have resulted in the new provisional model currently under consultation. Testing and community engagement to date indicates that the model will better reflect the complexity of biodiversity data leading to more efficient use of our community’s data in research and policy. The feedback we have received also indicates a steep learning curve for the future implementation of the data model. This feedback is essential for the development of publishing tools. This work aligns with the overall objectives of WorldFAIR by focused development on improving the interoperability of biodiversity data. Our FAIR Implementation Profile (FIP) will be enhanced by this improved functionality. This work promotes cross-domain interaction, as the Unified Model will enhance sharing of data in related Work Packages such as Agricultural Biodiversity, Oceans, and Geochemistry in the final portion of the WorldFAIR grant period. This work has been undertaken in alignment with the overall WorldFAIR goals, in particular WP02 on Engagement, Synthesis, Recommendations and FAIR Assessment. Visit WorldFAIR online at http://worldfair-project.eu. WorldFAIR is funded by the EC HORIZON-WIDERA-2021-ERA-01-41 Coordination and Support Action under Grant Agreement No. 101058393.