Optimal Power Flow problems are highly non-convex and nonlinear optimization problems of the power system. In this paper considered Voltage Deviation as a main objective function and minimize voltage deviation using different shunt connected Flexible AC Transmission (FACTS) devices like SVC and STATCOM. Metaheuristic Grey Wolf Optimization (GWO) Algorithm have been used for optimal setting of control variables to minimize the voltage deviation. To check the performance of proposed GWO algorithm it applied on the standard IEEE-30 Bus test system. Results of the paper have been clarified that use of the shunt connected FACTS device has given minimum voltage deviation.