ABSTRACT Recent years have seen a proliferation of experiments in deliberative democracy, with much focus on the internal workings and throughput legitimacy of such innovations as mini-publics. The research on the links between such mini-publics and the public is still in its infancy and there is a strong debate around the legitimacy of extending the outcomes of small-scale deliberation to the public. This Special Issue addresses the questions of legitimacy mainly from two broad perspectives; the input and the output legitimacy while some papers provide insights on throughput legitimacy as well. Input refers to the representativeness of participants from demographic, attitudinal and intersectional points of view. Output refers to whether the mini-public outputs reflect what the broader electorate would think and how representatives and policymakers deal with their outputs. The papers provide both theoretical and empirical discussion on participants' representativeness in mini-publics and politicians' potential involvement as well as issues of the whole process and how citizens perceive the legitimacy of mini-publics. Analysis also focuses on issues of attitudinal congruence of participants and its importance while other papers examine the impact of mini-publics to the wider electorate by also considering the role the preferences of policymakers have in the whole deliberative process. Theoretical contributions in this special issue analyze the theoretical implications of these democratic innovations for our understanding of democracy and the way forward.