Pay for success (PFS) offers an alternative approach to investing in the future, including early childhood education (ECE). An innovative mechanism for public-private partnership, PFS scales an evidence-based social program through up-front capital provided by a private or philanthropic funder. If a rigorous evaluation shows that the program achieved agreed-upon outcomes, the government repays the funder. If not, the funder takes the loss. The Pay for Success Early Childhood Education Toolkit is designed to guide jurisdictions and their partners through the core elements of a PFS project in ECE.