One of the promising ways for solving the water scarcity's problem in the world is distillation of the ocean's salt water by thermal methods. This method can be competitive with other methods, if required thermal energy is supplied by recovering the heat wastes of other energy systems such as gas turbine (GT) power plant. In this paper, a combined cycle of solid oxide fuel cell (SOFC) and GT can be used as thermal resource of multiple effect desalination system. Combination of these three system leads to reduce in total energy consumption, reduce in exhaust pollutants and reduce in operation and maintenance cost as well as increasing total efficiency in comparison with conventional individual systems. Exergoeconomic analysis of this hybrid system was performed to find out technical and economical optimal working point The system costs and revenues estimated, and the effect of two important design parameters (i.e., operational temperature and current density of SOFC) on exergy efficiency and levelized cost of electricity (LCOE) were investigated. Implementing GA optimization on the system and calculating the optimal values of the design parameter leads to rise of the exergy efficiency from 57% up to 63.5% and levelized cost of electricity was decreased to 0.0643 $/kwh. (C) 2017 Elsevier B.V. All rights reserved.