Social infrastructure requires a consistent and measurable definition and more evidence is needed to demonstrate why it is important to health, wellbeing and the liveability of a community. In this paper, social infrastructure is defined as life-long social service needs related to health, education, early childhood, community support, community development, culture, sport and recreation, parks and emergency services. These services are needed to promote health and wellbeing and underinvestment and poor planning of social infrastructure has been linked to area-based health inequities. Current methods used to plan infrastructure delivery in communities were analysed and a new conceptual framework of social infrastructure developed and empirically tested using geocoded health survey data linked to spatial social infrastructure measures. Both accessibility and mix of social infrastructure were associated with higher Subjective Wellbeing. Residents were most likely to have close access to childcare services, dentists, doctors and sport facilities and least likely to have access to services of culture and leisure including cinemas, theatres, libraries, museums and art galleries. Results provide evidence of direct associations between social infrastructure planning and public health, the need for alternative social infrastructure urban planning methods and policies, and areas for future research.