Inequality can have wide-ranging effects on communities, families and children. Income inequality (measured through the Gini index) was found to have an association with higher levels of peer violence in 35 countries (Elgar et al. 2009) and to influence the use of alcohol and drunkenness among 11- and 13-year olds (Elgar et al. 2005). On a macro level, countries with greater income inequality among children have lower levels of child well-being and higher levels of child poverty (Toczydlowska et al. 2016). More worrying still is that growing inequality reinforces the impact of socio-economic status (SES) on children’s outcomes, limiting social mobility. Concern about growing inequality features prominently on the current international development agenda. Goal 10 of the Sustainable Development Goals (SDGs) calls specifically to reduce inequality within and among countries, while the concept of ‘leaving no one behind’ reflects the spirit of greater fairness in society. But with a myriad of measures and definitions of inequality used in literature, the focus on children is often diluted. This brief contributes to this debate by presenting child-relevant distributional measures that reflect inequality of outcomes as well as opportunity for children in society, over time.