["Information Systems Journal, EarlyView. ", "\nABSTRACT\nSustainability has become a key priority for firms, and the increasing number of mandatory regulations only heightens its importance. The Corporate Sustainability Reporting Directive (CSRD) introduces stringent non‐financial disclosure requirements, significantly expanding the scope and breadth of reporting, particularly for those operating in industries with global and complex supply chains. A major challenge companies face with sustainability reporting is that it requires collecting, processing, and interpreting thousands of data points, which have not been systematically collected or analysed previously. While many companies tackle the challenges in a reactive, regulation‐by‐regulation manner, CSRD provides a unique opportunity to rethink and elevate sustainability data management to support forward‐looking sustainability initiatives and better decision‐making. To guide companies in managing sustainability data proactively, we introduce the Data Excellence Model (DxM) for Sustainability as a comprehensive data management framework that links regulatory demands to concrete business goals, organisational and technical enablers, and measurable results. We illustrate the framework through an exemplary front‐runner case of a leading European online fashion retailer and highlight key success factors and practices the firm undertook to holistically and systematically tackle the complex data requirements of CSRD. Building on the DxM for Sustainability, we outline a maturity assessment that companies can use as a diagnostic tool for proactive sustainability data management.\n"]