The central research question that this review sets out to investigate concerns the kind of interventions that research evidence suggests can lead to an expansion and improvement in girls’ education. It also considered evidence on the relationship between an expansion and improvement in girls’ education and a deepening of gender equality. A Theory of Change (ToC) was developed for the review. This drew on the understanding that girls’ education and gender equality are affected by processes within and beyond schools. It is therefore hypothesised that the development and implementation of interventions to improve girls’ schooling and enhance gender equality are affected by aspects of context at local, national and global levels. These include the level or extent of a climate of support for girls’ schooling, the existence of complementary legal and regulatory frameworks, and state capacity to implement policy and engage the widest range of stakeholders in inclusive dialogue.