In the present work, an ether-linked bisphenol-A diamine and cardanol-based benzoxazine was synthesized and its molecular structure was confirmed by FTIR and NMR. The benzoxazine-functionalized reduced graphene oxide hybrid material was prepared by solution blending technique and was incorporated into epoxy resin in varying (5%, 10% and 15%) weight percentages. The composites obtained were characterized by different analytical methods. Data obtained from mechanical studies inferred that there was a significant improvement in the values of tensile, flexural and impact strengths according to weight percentage incorporation of benzoxazine-functionalized graphene reinforcement. The values of dielectric constant are also enhanced according the weight percentage of reinforcement. Morphological properties of hybrid nanocomposites were analysed by SEM and XRD and the data obtained indicate that there was a uniform dispersion of reduced graphene oxide into the benzoxazine-epoxy matrix system, which was evidently well supported by the enhancement in the values of dielectric constant and mechanical properties. Among the different weight percentages of compositions used as reinforcement, 15 wt% C-bpda-rGo reinforced benzoxazine-epoxy composites possess better properties when compared with those of neat epoxy matrix and other weight percentages of hybrid nanocomposites. Data resulted from different studies infer that the hybrid composites developed in the present work possess an improved thermal, mechanical and dielectric properties suitable for high performance microelectronics applications.