After more than 25 years of research on girls' education, it is widely accepted among economists that investing in this area is one of, if not the most, effective development interventions. This research, as well as global advocacy and recent world events--including Malala Yousafzai winning the Nobel Peace Prize and the #Bringbackourgirls campaign after Boko Haram kidnapped hundreds of girls in Nigeria-- have helped make "girls' education" a household term. For a study published by The Brookings Institution in March 2015, the authors surveyed a group of 44 top funding institutions, two-thirds of which reported that in response to the growing support for girls' education, their budgets for this work had increased over the past 10 years. Their work, combined with global and national efforts to promote universal primary-school enrollment, has paid off: since 2000, there are 84 million fewer children and adolescents out of school; 52 million of these are girls (UNESCO & UNGEI 2015a). Yet despite the groundswell of support for girls there are 62 million girls out of school globally at the primary and lower secondary levels (UNESCO & UNGEI 2015b). Girls are still less likely to enroll in primary school, although boys are more likely to drop out of upper secondary school (UNESCO & UNGEI 2015a). This article asks what more can be done to address this?