To frame the discussion we introduce three key factors that underscore the importance of treating equality of educational opportunity as an independent concern, apart from theories of equality of opportunity more generally. These factors are: the central place of education in modern societies and the myriad opportunities it affords; the scarcity of high-quality educational opportunities for many children; and the critical role of the state in providing educational opportunities. These factors differentiate education from many other social goods. We follow this with a brief history of how equality of educational opportunity has been interpreted in the United States since the 1950s and the evolving legal understandings of equality of opportunity. Our subsequent analysis has implications for issues that are at the center of current litigation in the United States. But our philosophical discussion is intended to have wider reach, attempting to clarify the most attractive competing conceptions of the concept.