A fit-for-purpose Data Management System (DMS) is a critical infrastructure underpinning the successful delivery of the Reef 2050 Integrated Monitoring and Reporting Program (RIMReP) and related reporting activities, management systems and decision support tools. The architecture of the DMS is conceived as a data storage and access service and associated automation tools based on open standards. It includes a data API, which provides real-time access to datasets in a range of standard formats, and a metadata API, which enables the discovery of the data accessible in the DMS. From an initial scoping assessment, we identified 153 unique datasets from 73 organisations or programs. Based on existing and anticipated use cases, 55 datasets were identified as a high priority and 43 as medium priority. Approximately 50% of the high-priority datasets come from providers with good data infrastructure. By June 2024, the DMS will be a fully operational system capable of harvesting, storing and delivering most of the datasets related to the GBR, providing the required data for current and future management needs.