AbstractThe focus on fillers' influence in high‐performance polymer composites has undergone a transformation. Additionally, the utilization of additive manufacturing (AM) in this venture has aroused the curiosity of investigators to empirically enumerate the characteristics of such composites for numerous applications. Consequently, this investigation aims to assess the thermal behavior of polyethylene terephthalate glycol (PETG) polymers reinforced with graphene flakes. As mentioned above, various weight ratios of the constituents are manufactured, blended, and extruded into six distinct varieties of 3D‐printable filaments utilizing a twin‐screw extruder. In accordance with the relevant American Society for Testing and Materials (ASTM) standards, we perform the thermal characterization of the compounded PETG/graphene pellets using Fourier transform‐infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results reveal that enhancing the concentration of graphene augments the thermal properties of the composites. Furthermore, the FTIR investigation contributes to graphene's proficiency in absorbing infrared radiation and curbing micro‐vibrations. Additionally, the study highlights the way in which chemical interactions between graphene and PETG impact the general effectiveness of the composites.