This chapter examines the role of private actors in raising, allocating and implementing international development aid (understood as resources supposedly intended to lastingly improve the well-being of individuals and groups in another country). Private individuals and non-governmental organizations (NGOs) have long been important actors in the transnational governance of economic development through aid. Yet some private actors, such as foundations providing funds for development projects in other countries, have become much more prominent in international development during the last two decades while others, such as NGOs, have become far more numerous or have taken on new roles. Increasingly, an analysis of global economic governance through development aid without attention to these private players is not just incomplete but is likely to result in biased analyses and misguided policy advice.