A flexible and stable supercapacitor electrode material consisted of reduced graphene oxide (rGO)/PEDOT:PSS nanocomposites. The SEM images showed a transparent sheet-like structure for the rGO–PEDOT:PSS composite, while the GO–PEDOT:PSS composite appeared thick and opaque. The homogeneous mixing of rGO and PEDOT:PSS with each other makes the composite transparent. The XRD result showed the appearance of peaks at 24.5° and 10.8° for rGO–PEDOT:PSS and GO–PEDOT:PSS, respectively, confirming the successful synthesis. The calculated interlayer spacing between the layers of GO–PEDOT:PSS was 8.1 Å and for rGO–PEDOT:PSS, it was 3.6 Å. The Raman spectra showed sharp peaks at 1260.4, 1427.7 and 1557.2 cm⁻¹, confirming the presence of PEDOT:PSS layers in both GO–PEDOT:PSS and rGO–PEDOT:PSS. From the ATR–FTIR spectra of PEDOT:PSS, adsorption peaks at 860.5 and 945.3 cm⁻¹ were confirmed for the C–S and S–O stretching vibrations derived from the thiophene ring. Furthermore, the rGO–PEDOT:PSS obtained a maximum specific capacitance of 465 and 237.6 F g⁻¹ from cyclic voltammetric analysis at 5 mV s⁻¹ and Galvanostatic charge–discharge curve at a current density of 10 A g⁻¹. The value of the specific capacitance of rGO–PEDOT:PSS was higher than that of PEDOT:PSS and GO–PEDOT:PSS. The combined properties of rGO and PEDOT:PSS and the synergistic effect produced help to enhance the supercapacitive property of rGO–PEDOT:PSS with excellent stability.