Despite worldwide commitments to provide universal primary and secondary education, there has been little progress in reducing the number of out-of-school children in Sub-Saharan Africa, and this issue is expected to be further compounded by the COVID-19 pandemic with many children not returning to schools. The issue is particularly prominent among rural girls who—facing cultural, systemic and structural barriers—either never enroll or drop out before completing their education. The Back2School Project will address this issue among girls in rural communities in Ethiopia, Kenya, and Tanzania by refining the accelerated learning model for out-of-school children called Complementary Basic Education in Tanzania (COBET) with the aim of further enhancing it in Tanzania and generating evidence in support of scaling its key elements in Ethiopia and Kenya. The project will review and improve the COBET model, generate evidence about the effectiveness of its key elements across three countries, and produce knowledge about how the key elements could be adapted and scaled in Ethiopia and Kenya. Selected through a competitive call process, the project will be implemented by the Graca Machel Trust and the African Child Policy Forum.