This brief reviews two complementary spheres of international cooperation, in which blended finance is predominantly used. First, in international climate finance, following the developed country pledge to mobilise USD 100 billion per year in public and private finance - starting in 2020 - and the recently published “road map” to meet this goal. Second, in official development assistance (ODA), and the related blended finance facilities within the European Union (EU) that provide funding to projects supporting the delivery of the UN Sustainable Development Goals. To date, the climate finance sphere has led the way on blended finance, acknowledging the critical role private investments need to play in tackling climate change. This experience will prove useful as blending expands as a part of ODA.