Even before COVID-19 left as many as 1.6 billion students out of school in early 2020, millions of children and youth around the world did not have access to the quality education they needed to lead healthy, safe, and productive lives. Even worse, the poorest and most marginalized children continue to be most affected by this learning crisis, losing out on their right to education. This situation has far-reaching consequences for generations to come, including on poverty, inequality, climate change, and public health. Urgent action must be taken to rapidly and sustainably expand access to high-quality learning opportunities for all children. Of course, the question is “how?” While there exist many innovations that improve children’s learning, the vast majority only reach a small fraction of children in need. As a result, there is growing demand for more evidence and guidance on how to identify, adapt, and scale cost-effective policy and practice that lead to millions more children learning.