In this paper, the Firefly Algorithm (FA) is proposed to find the optimal solution for the Optimal Power Flow (OPF) problem in a power system. The proposed algorithm is applied to determine the optimal settings of control variables of the OPF problem. The performance of the proposed algorithm was examined and tested on the standard IEEE 30bus test system with different objective functions and compared to other methods reported in the literature recently. Simulation results clearly obtained from the proposed (FA) approach indicated that (FA) provides an effective and robust high-quality solution for the OPF problem.