Agency, understood as the capacity to act independently and to make one's own choices, is considered central to children's development. Thus, education, and hence education curricula, have a role in the development of learner agency. While curriculum development is a key focus for educational theory, research, policy, and classroom practice, the potential implications of curriculum content selections for learner agency remain underexplored. Theoretically, this paper engages with critical realism, explaining how it can provide theoretical foundation for a more comprehensive view of learner agency and, by implication, more balanced curricula. Empirically, the paper draws on the findings from a content analysis of the national curriculum documents of four countries with relatively high scores in international comparative tables, England, Australia, Hong-Kong, and Canada, to develop a new typology of primary curricula. Based on the extent of emphasis placed on knowledge versus skills, values, and attitudes, three types of curricula were identified: knowledge-based, skills-oriented, and learner-centred. Due to its significant theoretical and practical influence globally, we focus on the knowledge-based model and its likely impact on students' agency. We conclude by highlighting the importance of making learner agency a key orientation of the curriculum and suggesting directions for future research.