Ion-conducting ceramic membrane reactors offer an opportunity to combine membrane separation processes directly with chemical reactions, leading to process intensification and, hence, benefits with regard to efficiency. Current research activities focus on membrane reactors due to their high intrinsic efficiency and great potential for the production of a large variety of commodity chemicals, energy carriers, and synthetic fuels. This includes the reduction of CO2 emissions and the utilisation of CO2. In this review, different concepts and principles of membrane reactor operation are presented followed by a comprehensive overview and discussion of different application cases. These applications are clustered according to the targeted products. The article discusses and evaluates the potential of the different concepts from the authors' current perspective. We have not undertaken a ranking with respect to cost efficiency, process efficiency and applicability since the development levels are very different and in general at very low technology readiness levels (TRLs). However, the demonstration of one (or a few) membrane reactors at a commercially relevant size and price is urgently required in order to initiate more focussed research and development. The present review of membrane reactors aims to provide a broad overview of ongoing research activities regarding ceramic ion-conducting membrane reactors within the last ten years in the light of sustainable energy and chemical production.