Well-being is generally acknowledged as a complex concept, and leading discourses are rooted in disciplines such as philosophy, psychology and economics. Despite a wealth of theoretical explanations, child well-being is largely under-theorised. Some argue it is unlikely that philosophical discourses of well-being will straightforwardly be extended to children because they were not originally written with them in mind. Therefore, this article first examines dimensions, domains and discourses of well-being and summarises the discussion with a conceptual framework in order to provide clarity about a complex concept. Second, the article discusses current research about the meaning of child well-being and finds that while there are different terms in use, many discourses are similar in nature. Third, the article shows how knowledge and understanding of early childhood relates to various well-being discourses and suggests that a theory of child well-being may not be needed. The article highlights the new development emerging between psychology, economics and sociology and concludes by discussing the value of adopting multi-disciplinary perspectives of well-being. The article is useful for policy-makers, practitioners and researchers in understanding the complex nature of well-being, particularly in the context of early childhood education.