Polymeric nanocomposites are generally lighter and stronger that hold key features for many industrial applications, such as aerospace, automotive, defense, packing, electrical and electronics, biomaterials, sensors, energy, and consumer products. Their exceptional mechanical, electrical, chemical, and thermal properties help bring these materials as one of the prime focus areas in the world. Extensive research studies involving thermoplastics with nanofillers (TiO2, graphene, carbon black, and carbon nanotubes) have been conducted to produce various nanocomposites. The prime objective of this study is to develop polymeric nanocomposites by incorporating nanoparticles of graphene into polyacrylonitrile (PAN) thermoplastic where fiber reinforcement bonding is used to enhance the mechanical properties leading to very high strength-to-weight ratio polymeric nanocomposites. A mixing ratio of 20:80 for PAN and dimethylformamide (DMF) solvent was used to dissolve the PAN power using magnetic stirring. Graphene nanoparticles were then added to the solution at 0-4 wt.% ratio after which the nanocomposite coupons were prepared by casting the PANbased resin in aluminum grooves where carbon fibers and SiC fibers were placed as reinforcement materials to make them robust. After curing at room temperature, the coupons were oxidized at 200°C for 2 hours in air and then carbonized at 650°C for additional 2 hours in Ar gas. The subsequent testing and characterization studies, such as tensile, Fourier-transform infrared spectroscopy (FTIR), and water contact angle have been conducted on the prepared nanocomposites. The obtained test results indicated that the mechanical and thermal properties have been significantly enhanced after the addition of a small percentage of nanoparticles into the PAN solution. This enhancement can be attributed to the fact that the surface-to-volume ratio is high for nanoparticles, thereby making them more resilient compared to traditional composites.