The absence of a sociological discourse about children in the past meant that child and family social work has largely relied on psychological interpretations of children and their behaviour. However, since the 1990s, the sociology of childhood has been developed in the UK. The aim of this paper is to explore the relevance of the sociology of childhood in understanding looked‐after childhoods and in informing contemporary social work practice with looked‐after children and young people. The central argument of this paper is that, in order to fulfil professional responsibilities and to implement current and forthcoming UK social policies for looked‐after children, social work needs to employ broad understandings of children, young people and looked‐after childhoods. The paper goes on to discuss the ways in which a social work approach drawing on the sociology of childhood can offer such a conceptualization.