Concrete production involves using vast quantities of ordinary portland cement (OPC), the primary binder material. However, OPC production uses high embodied energy and emits more CO2 into the atmosphere. One of the alternatives is using industrial waste or byproducts such as fly ash (FA) and ground granulated blast furnace slag (GGBS) as supplementary cementitious material. However, the main drawbacks of conventional concrete with or without supplementary cementitious material are its brittleness and lower elasticity. This led to the addition of fibers to concrete. In this study, the effects of macro synthetic fibers (MSF), 20% FA class F, and 20%, 25%, 30%, 35%, and 40% GGBS were used as supplementary cementitious materials to produce MSF-reinforced binary concrete of grade 40 MPa. MSF of aspect ratio 36 was added to the mix at 0%, 0.25%, 0.5%, 1%, 1.5%, and 2% by volume fraction. The results showed that the MSF fiber-reinforced binary workability decreased with an increase in the addition of MSF. SP22 (i.e., 1.5% MSF, 20% FA, 30% GGBS) specimens yield good results, and higher strength. Furthermore, the mechanical performance of all samples improved significantly with an increase in the percentage of the volume of MSF. Incorporating MSF, GGBS, and FA reduces OPC usage, enhances strength characteristics, and contributes to cost reduction in construction.