The Academic Citizens’ Assembly (ACA) is a model of a citizens’ assembly built on academic principles (evidence-based, lobby-free, no ideology), open to the whole society and, using a novel process and tools, scalable to potentially include millions of participants. This deliberative and participative approach builds on the Swiss tradition of direct democracy and aims to bridge the gap between high-quality deliberation and decision-making of past citizens’ assemblies, and the legitimacy of direct democracy.