Natural resource-driven approaches to bioengineering plastics are being developed to compete in the automobiles, power, and other sectors. Polytrimethylene terephthalate (PTT) is a particular of them, and it was chosen for the current investigation to build an advanced nanocomposite material. Using a twin-screw micro compounder, injection moulded PTT/Graphene-Oxide (GO)/Carboxyl functionalized Multiwall Carbon nanotube (f-MWCNT) hybrid nanocomposites were prepared. The impact of GO and f-MWCNT reinforcement on the composite's thermal and mechanical characteristics of hybrid nanocomposites was examined. GO was synthesized from the graphite powder by modified Hummer's method and MWCNTs were functionalized using the concentrated sulfuric acid (H 2 SO 4 ) and nitric acid (HNO 3 ) with a volume ratio of 3:1 in an ultrasonic bath at room temperature. In all formulations, the investigation was done at a constant filler amount of 2 wt%. To understand the chemical interaction between PTT and nanofiller, Raman spectroscopy was used and to examine the state of dispersion, scanning electron microscopy (SEM) was systematically analysed. In comparison to pristine PTT, the water absorption, tensile strength, flexural strength and impact strength of hybrid nanocomposites were improved marginally. It was also observed that GO has more prominent in increasing the mechanical properties of the hybrid and f-MWCNT in thermal properties. The 3-D geometrical bridge between GO (2-D) and f-MWCNT (1-D) made the hybrid more dispersible and effective for different applications.