The Sustainable Development Goals target of leaving no one behind has stalled because out-of-school children (OOSC) in Africa are generally poor, disabled, orphaned, minority, working, overaged, child-brides and are remote. Descriptive statistical analysis of quantitative secondary data was applied to investigate education issues. Comparisons across gender, residence and regions indicate marginalisation in education systems characterised by low preschool education, inefficient primary schools evidenced by insufficient inputs, untrained, poorly paid teachers and biased public expenditure. OOSC face a range of circumstances: to meet Sustainable Development Goals targets requires solutions to specific cases; one size will not fit all, since OOSC are trapped in a web of multiple problems.