This study investigates the effect of interfacial features on the mechanical and electrical properties of reduced graphene oxide (rGO)/aluminum (Al) composites. The composites were fabricated using a hybrid process that includes chemical and mechanical methods. First, GO was uniformly dispersed on the surface of Al powder via a solution process. A strong interface was formed between GO and Al via several chemical bonds by using polyvinyl alcohol (PVA) as an organic binder during the solution process. Then, GO was thermally reduced to rGO, wherein the interfacial features were varied according to the atmosphere (vacuum or H-2(10%)/N-2(90%) mixed gas). Subsequently, rGO was mechanically embedded and further dispersed within soft Al powder through the plastic deformation of Al. Vacuum was found to be more effective than the mixed gas at removing functional groups containing oxygen in GO and therefore generated a tighter interface. As a result, the composites containing rGO that were reduced under vacuum showed higher strength and lower ductility compared with those reduced under the mixed gas. Conversely, the interfacial features rarely affected the electrical conductivity of the composites because the electrical conductivity of rGO was considerably lower than that of Al. Consequently, compared with their monolithic counterparts, the composites containing only 0.2 vol% rGO showed a 374-MPa yield strength without a significant loss of electrical conductivity, thereby demonstrating their potential feasibility in electrical and electronic applications.