The aim of the study is to propose an optimization approach for optimum design of tuned mass dampers (TMDs) implemented to seismic structures considering soil-structure interaction (SSI). In the methodology, two metaheuristic algorithms such as harmony search algorithm and bat algorithm were employed. The present approaches evaluate time domain analyses of structure and consider the responses under several earthquake records. The optimum design variables defined as mass, period and damping ratio of TMD were searched for the optimization objective (minimization of the maximum displacement of structure) and the design constraint (limitation of the scaled stroke of TMD). The proposed methods were presented by using single degree of freedom structures for different soil characteristics, main structure periods and damping ratios. Also, a 40-story high-rise structure was investigated. For the 40-story structure, the optimally tuned TMDs are effective to reduce the critical displacement up to 25%. The proposed methodologies are both effective and feasible, but bat algorithm has advantages on the minimization of the optimization objective and finding a precise optimum value.