Various researches in optimization of cantilever retaining wall were proposed in the past, none of them considered geotechnical requirement of slope stability in the optimization problem. The objectives of this research are: 1) to develop an efficient technique for optimal design of conventional reinforced concrete cantilever retaining wall including complete geotechnical considerations, namely, overturning, sliding, bearing capacity, and slope stability as well as structural requirements; and 2) to extend capability of the developed method in the first objective for optimal design of integral bridge abutment retaining wall. In this study, the design variables of the proposed method are dimensions of the wall and steel reinforcements in each wall component. The objective function, three basic geotechnical constraints of wall failures (overturning, sliding, and bearing) as well as required structural reinforcements followed the same method of the optimization problem presented in the past. To take into account of slope stability in the optimization problem, the factor of safety based on the Ordinary Method of Slice is derived analytically in terms of unknown variables of wall dimensions and the center of circular arc failure surface. For integral bridge abutment, additional constraints for combined axial compression load and bending moment are included in the system of nonlinear constraints of the retaining wall optimization. The capabilities of both proposed methods are demonstrated through their applications in varieties of general retaining wall problems.