This protocol sets out the rationale and method for a Realist Synthesis Review (RSR) of the global scholarly literature on multi-stakeholder forums (MSFs) set up to address land use and land-use change at the subnational level. The review engages in the systematic and comparative analysis of how contexts affect the outcomes of MSFs. These forums are set up as purposely organized interactive processes that bring together a range of stakeholders to participate in dialogue, decision making and/or implementation regarding actions seeking to address a problem they hold in common or to achieve a goal for their common benefit. The growth of MSFs related to land use/land-use change reflects the awareness that environmental problems cannot be addressed without the effective engagement of the actors that determine land-use practices on the ground; nor can such problems be resolved within a conservation community when the drivers are located in other sectors. MSFs may produce more effective and sustainable outcomes by getting those sectors and actors that have commonly held contradictory development priorities to coordinate and align goals through discussion, negotiation and planning. In contrast, MSFs may also be an expedient way to implement top-down approaches and create the illusion of participation. Scholars and activists note that ‘MSF’ may reify top-down approaches, and take the ‘participation’ of local stakeholders for granted in box-ticking exercises to please donors. This review is a timely examination because MSFs have received renewed attention from policy makers and development and conservation practitioners, in light of the growing perception of urgency to address climate change and transform development trajectories. Through this review, we aim to contribute empirically to the study of MSFs and similar participatory processes, but also methodologically to the social sciences more generally through the application of the RSR over the more common systematic review.