Despite the increasing recognition of the significance of children's own perceptions of inequality and critical theorisations of, and much research on, the impact of inequality on human agency, there is a lack of empirical evidence on the impact of inequality on children's agency. This paper contributes to addressing this gap by exploring how children's perceptions of inequality impinge upon their perceptions of the efficacy of their agency with regard to their occupational choices. It uses questionnaire data from a sample of 862 South Korean school children aged 10-18 from diverse socioeconomic backgrounds and follow-up semi-structured interviews with 42 selected children. The findings suggest that, while most of the children held meritocratic beliefs about academic and economic inequalities, some subtle but significant relationships existed between the children's perceptions of inequality, their socioeconomic status and their perceptions of their agency. The older children were significantly more likely both to be aware of their relative academic and economic positions and to have given up a desired occupation in response to their perceptions of the inefficacy of their agency. Across the sample as a whole, in the processes by which the children adjusted their future occupational ambitions, while their socioeconomic status (especially in terms of the father's occupation) had a significant impact, the children's awareness of their relative positions, especially their economic position, showed a more pervasive and significant relationship with their likelihood of having given up a desired occupation due to having perceived the inefficacy of their agency.