In recognition that the coming century will see a substantial majority of the world's population living in urban areas, the World Health Organisation and the United Nations have developed policy frameworks and guidance which promote the increased provision of urban green space for population health. However, these undertakings do not provide specific guidance for urban policy in terms of the particular design attributes required to tackle lifestyle illnesses and to promote well-being in urban populations. Furthermore, green spaces have generally been treated as a homogenous environment type. In order to address these weaknesses, this paper collates and reviews the evidence linking health, well-being and green space using a life-course approach. The literature generally endorses the view that urban green spaces, as part of the wider environmental context, promote health and well-being across the life course. Based on the evidence, cohort-specific and cross-cutting design interventions are identified and a general integrated green space framework for health and well-being is proposed. This analytical lens facilitates distillation of a vast quantum of research and the formulation of specific planning and design guidance for the provision of more inclusive green spaces that respond to the varying needs of people across all life-course stages.