AbstractA new motivation for marine restoration has been observed, associated with the dissatisfaction with current marine restoration governance arrangements (MRGAs). An MRGA consists of alliances of public and private actors (coalitions) who, through their common conceptualisation of the problem (discourses), try to influence and design marine restoration activities while considering the rules of decision‐making, and the management of limited resources. Emerging MRGAs rise in parallel to existing ones and aim to contribute to the same goals or show another way of reaching those goals. This phenomenon raises questions of legitimacy both for the emerging and the existing arrangement. Building on existing literature, this paper proposes an analytical framework to simultaneously explore input, throughput and output legitimacy as three essential pre‐conditions of legitimacy for MRGAs. The framework is tested in three European cases of MRGAs that were part of the European Union MERCES project (http://www.merces-project.eu/). Analysis showed that actors who are influential in achieving restoration goals, and also those who are impacted by restoration actions, should be involved in the MRGAs (input legitimacy); actors within MRGAs should establish and follow procedures for decision‐making that are both transparent and clear (throughput legitimacy); and actors within MRGAs need to establish a common understanding of restoration, of the goal to reach and of the related uncertainties (output legitimacy). Awareness of these pre‐conditions allows actors internal and external to MRGAs to address aspects that give legitimacy to restoration actions. It also creates a language that allows actors to engage in discussion on legitimacy that goes beyond the mere application of the rule of law.