In this study, a hybrid organic–inorganic material based on polypyrrole (PPy), graphene nanoplatelets (GNPs), and bismuth oxide nanoparticles (Bi 2O 3) was developed to overcome the limitations of organic materials’ thermoelectric (TE) conversion efficiency. The GNPs were decorated with Bi 2O 3 nanoparticles using a simple and effective method based on infrared irradiation and diazonium chemistry. The synthesized nanocomposites were characterized using various techniques such as X-ray diffraction, Transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy to examine the structural and physical properties. The results of this study showed a promising improvement in electrical conductivity (σ) and Seebeck coefficient (S) of PPy/GNPs-Bi 2O 3 compared to pure PPy, attributed to the π–π stacking between PPy chains and GNPs surface. Bi 2O 3 enhances the TE behavior of the nanocomposite by improving charge transport and binding both components (PPy and GNPs). At room temperature, the power factor was found to be 11 times higher (1 µW m −1 K −2) compared to pure PPy. Further exploration at high temperatures could result in higher TE performance. Graphical abstract: [Figure not available: see fulltext.].