Quasi-static and dynamic compression response of conventional and 0.1-0.3 wt% CNF (Carbon nanofiber) incorporated glass fiber reinforced polyester composites (GRPC) were measured. A high intensity ultrasonic liquid processor was used to infuse CNF into the polyester matrix which was then mixed with a catalyst using a high speed mechanical agitator. SEM (Scanning electron microscopy) revealed best dispersion of CNF in the 0.2 wt% CNF-loaded polyester matrix. Quasi-static (at low strain rate, 10 -3 s -1 ) compression tests performed on conventional and 0.1-0.3 wt% CNF-loaded GRPC revealed 43% and 60% increase in strength and modulus, respectively, over the conventional sample. High strain rate compressive strength and modulus of nanophased GRPC were characterized using SHPB (Split Hopkinson pressure bar). At strain rates of 550, 700, and 800 s -1 compressive strength and modulus were observed to be enhanced by 31% and 64%, respectively, over static values. Fracture morphology studied by both OM (Optical microscopy) and SEM revealed fiber kinking and shear fracture at low strain rates and fiber-matrix debonding, delamination, and fiber breakage dominating at high strain rates. The extent of damage was more pronounced in the conventional composite compared to nanophased ones.