Solid electrolytes have found applications in several areas, including (a) sensors, (b) separators, (c) solid oxide fuel cells, and (d) solid-state batteries. In addition, solid electrolytes have been used in the construction of solid electrolyte cell reactors (SECRs), in which heterogeneous catalytic reactions have been studied. Also, SECRs have been used as chemical cogenerative fuel cells, i.e., for the simultaneous production of electricity and useful compounds. In the present work, a survey of the studies conducted in SECRs is presented. The fundamental operating principles, results in technologically important reactions, and the hurdles that should be overcome to bring SECRs into industrial practice are discussed.