This paper reviews the studies on transmembrane redox reactions and redox reaction-driven ion transport in artificial membrane systems. These systems consist of an electron donor, an electron acceptor and the membrane (bilayer lipid membrane or organic liquid membrane) containing redox mediators and/or photosensitizers. Spontaneous and photosensitized redox reactions across the membrane are discussed with reference to the reaction mechanism, the property of the redox mediator and so on. Then, ion transport coupled to a redox reaction is described and its mechanism is discussed.