Influential reports about the "learning crisis" in the global South generally pay insufficient attention to social inequalities in learning. In this study, we explore the association between family socioeconomic status and learning outcomes in 10 francophone African countries using data from the Programme for the Analysis of Education Systems, a standardized assessment of pupils' mathematics and reading competence at the end of primary school. We start by showing that learning outcomes among grade 6 pupils are both poor and highly stratified. We then develop and test a conceptual framework that highlights three mechanisms through which family socioeconomic status might contribute to learning: (1) educational resources at home, (2) health and well-being, and (3) differences in school quality. We find that most of the effect of family background on learning outcomes operates through school quality, which results from a combination of the unequal distribution of resources (such as teachers and textbooks) across schools and high socioeconomic segregation between schools. On the basis of these results, we suggest that most countries in the region could improve equity as well as overall performance by "raising the floor" in school quality.