Meritocracies are social systems in which individuals are rewarded strictly on the basis of their performance. Meritocracies accept wide inequalities in educational or socioeconomic outcomes, but require rigorous equality of opportunity to be effective. Meritocratic systems operate in sharp contrast to systems based on kinship, nepotism or any form of inherited privilege. Modern societies are increasingly education-based meritocracies in which schools identify and cultivate skills and effort. This chapter examines the role of meritocracy throughout the socioeconomic life cycle, paying particular attention to variations in meritocratic processes between and within nations.