As an international mega-event of historic proportions, COP21 and its host city drew global attention and attracted many of the most prominent and active players in the international climate regime. In the innumerable reports, articles and studies devoted to the UNFCCC process, one group of actors involved in and around the Paris COP seems to have gone largely unnoticed: philanthropic foundations. This is fairly surprising given that foundations, in their grant-making and convening capacities, have historically supported and contributed to the UNFCCC process. In the days following the Paris COP, members of the foundation community, who traditionally tend to keep a low profile, openly stressed their role in the agreement. According to the European Climate Foundation (ECF 2016), “although we should be careful not to overstate our role, it is important to recognise that the climate philanthropy community’s activities prior to and at the COP helped to lay the basis for the outcome.”