This study responds to the request from the Green Climate Fund (GCF) Board, at its seventeenth meeting, to develop guidance on the GCF’s approach to adaptation. Its goal is to inform the GCF Secretariat’s work in generating such guidance. As an operating entity of the financial mechanisms of the UNFCCC, Kyoto Protocol, and the Paris Agreement, the GCF plays a vital role in supporting adaptation in developing countries. It is mandated to allocate 50 percent of its resources, in grant equivalent terms, to adaptation efforts and to channel at least 50 percent of those funds for adaptation to Least Developed Countries (LDCs), Small Island Developing States (SIDS), and African countries.