This research examines the impact of glass fiber stacking and fiber configuration on the flexural characteristics of unsaturated polyester resin (UPR) composites. Two fiber topologies, Chopped Strand Mat (CSM) and Woven Roving (WR), were combined in different arrangements with 1 to 4 layers and produced utilizing the hand lay-up technique. Flexural testing was performed in accordance with ASTM D790 to assess the efficacy of each composite arrangement. The findings indicated that augmenting the number of CSM layers improved both flexural strength and modulus, with optimal performance seen in the four-layer laminate. Moreover, hybrid configurations that integrate WR and CSM exhibited considerable diversity in flexural behavior based on layer arrangement. The optimal design was WR–CSM–CSM–WR, with a flexural strength of 156.21 MPa and a modulus of 8.54 GPa. Failure study revealed that WR on the outside layer enhanced load resistance and resin wetting, but CSM in the core improved interlaminar shear strength. Conversely, the accumulation of pure WR or the application of CSM on the surface diminished performance owing to the creation of voids and inadequate stress transmission. This work emphasizes the significance of optimum layer design in improving the mechanical performance of UPR/GF composites for structural applications.