Australia has made tremendous progress in building a better early childhood education and care (ECEC) system to serve all Australian children and families. Substantial data already exists about ECEC services in Australia, including access, participation and quality. Large-scale data sets are held by governments (state and federal), research organisations, and sometimes by ECEC providers themselves. Yet these data are not fully utilised to investigate what makes the most difference for children's learning and development. This scoping report maps the existing ECEC data landscape in Australia, and identifies opportunities for data to be better used to support children's learning and development. It builds on a substantial body of work already underway across governments and research in improving ECEC data use, which is continuing to evolve as the data architecture becomes more sophisticated. This scoping report signals promising projects, as well as enduring gaps that need to be addressed. This report aims to guide and catalyse further work towards this long-term vision, including by the Australian Education Research Organisation (AERO) and its partners across the ECEC sector, policy and research.