This review examines several dimensions of ECEC in relation to the recent growth in income inequality. Part I briefly reviews trends in income inequality and the wage, labor supply, and family composition factors that have interacted to increase inequality in recent decades. Part II reviews the current state of knowledge about three potential links between early childhood education and care (ECEC) and inequality: (1) disparities in families’ child care cost burdens and employment disincentives, (2) inequalities in children’s enrollment in formal and educationally-oriented modes of care and in the quality of care, and (3) short- and long-term consequences of ECEC experiences and quality for children’s cognitive development, socio-emotional adjustment, and health. We use a combination of literature review and original data analyses to summarize the state of knowledge on these relationships and identify key areas for future research. Part III provides an overview of major public policies for financing child care and improving child care quality and comments briefly on what is known about the contribution of government. Part IV concludes by summarizing what is known, and what remains to be learned, about the associations between inequalities in ECEC and income.