The rise of an elite private philanthropy is one of the main highlights of the past two decades. Evolving more and more in a partnership logic with governments and community groups, philanthropy, and most specifically “investment philanthropy,” is a major player in the emergence of “social governance.” From the cases of the Harlem Children’s Zone—a non-profit organization in New York—and the Fondation Lucie et André Chagnon in Quebec, this comparative study analyzes how the triangular relationship between philanthropic, community and public actors affects the development of social policies. This study highlights how social governance contributes to a reconfiguration of the links between the State and civil society and to a certain openness in public policy processes. But it also tells us about the limited nature of this openness, about the balance of power within this process, and about the evolution of relations between the State and civil society in two North American contexts.