This theoretical paper addresses fundamental questions raised by a four nation comparison of child welfare interventions in the UK, the Child Welfare Inequalities Project, which has highlighted differences between and within countries. The Project analysed administrative data to examine the relationship between deprivation and state intervention. This Project builds on research by Coventry University which established both a social gradient in child welfare interventions and an inverse intervention effect similar to the inverse health law (better health care in more affluent areas). These empirical findings raise, but do not fully answer, whether such inequalities in child welfare interventions should be addressed. In order to consider this complex question this article aims to explore theoretical ideas from other disciplines to provide important perspectives on such inequalities. These perspectives include ideas from political theory, psychology and moral philosophy. They suggest that child welfare should be: structured in a fairer way (based on Rawls' work on justice); that people think society is more equitable than it is and would prefer it to be more equally distributed (based on Norton and Ariely's work on attitudes to inequality); and that it is ethically irrational not to address this (based on Singer's work on moral distance).