The Seeding Success data resource was established to investigate child health and health equity in Australia’s most populous state, New South Wales (NSW), with a focus on Aboriginal and Torres Strait Islander children. The data resource includes a population-based cohort of children who were born in NSW and started school in 2009 or 2012, identified from the Australian Early Development Census (AEDC). In total, data are available for over 166,000 children, of whom 10,430 children (6.3%) were identified as Aboriginal and/or Torres Strait Islander. Data are also available for the mothers of 98% of the children, as well as the second parent of 23% of the children. Within the resource, the health and development trajectories of the child cohort are retrospectively tracked from birth to school age using probabilistic data linkage.