The past decade has seen a frontier open up in international development engagement with the entrance of new actors such as celebrity-led organisations. We explore how such organisations earn legitimacy with a focus on Madonna’s Raising Malawi and Ben Affleck’s Eastern Congo Initiative. The study draws from organisational materials, interviews, mainstream news coverage, and the texts of the celebrities themselves to investigate the construction of authenticity, credibility, and accountability. We find these organisations earn legitimacy and flourish rapidly amid supportive elite networks for funding, endorsements, and expertise. We argue that the ways in which celebrity-led organisations establish themselves as legitimate development actors illustrate broader dynamics of the machinery of development.