Interest in children's wellbeing has been steadily increasing across political, social and educational contexts. While the importance of children's wellbeing--particularly in relation to learning and development--is undisputed, there are conflicting perspectives on what "wellbeing" actually is, let alone how to measure and promote it. The purpose of this paper is to examine the context, complexities and challenges associated with understanding children's wellbeing--specifically children's perspectives on their wellbeing in the early childhood setting. This paper argues that in order to support children's wellbeing in early childhood settings, we need to know how young children subjectively experience wellbeing. This requires the adoption of a constructivist, child-centred approach to the conceptualisation of wellbeing in early childhood research to promote effective programme provision.