Mean–variance mapping optimization (MVMO) is a new population-based metaheuristic technique which is successfully applied for different power system optimization problems. The special feature of MVMO is the mapping function applied for the mutation based on the mean and variance of n-best population. Recently, the modified version of MVMO has been developed to become more powerful, named as swarm-based mean–variance mapping optimization (MVMO^S). This paper proposes MVMO^S as a new approach for solving the economic dispatch (ED) problem considering valve-point effects. To validate the performance of the proposed method, the MVMO^S is tested on three systems including 3, 13, and 40 thermal generating units with valve-point effects and the obtained results from MVMO^S are compared to those from other existing methods in the literature. Test results have indicated that the proposed MVMO^S is more robust and produces better solution quality than many other methods. Therefore, the MVMO^S is efficient for solving the ED with valve-point effects.