Herein, the synthesis of Polyaniline‐Eri nanosilk fibroin (PANI/ENSF) composite supercapacitor electrode material by utilizing Eri silk (Philosamiaricini) as a raw material and polyaniline (PANI) with H2SO4 as doping acid and (NH4)2S2O8 as an oxidant, via a simple in situ oxidative polymerization technique, with good performance characteristics is reported. The chemical composition of the composites have been studied by using XRD, FT‐IR, UV–vis spectroscopy, Raman spectroscopy, and morphology is studied by SEM. BET analysis reveals that the surface area of composite is 712.10 m2g−1, and BJH analysis shows that the pore size is mainly concentrated between 1.5 and 15.7 nm. The composite shows electrical conductivity of 17.33 × 10−2 Scm−1 (Keithley Model 2000). The electrochemical performances are evaluated by using CV, GCD, and EIS measurements. The three‐electrode system composite shows specific capacitance of about 310.12 Fg−1 at 0.1 Ag−1, which is the highest value being reported, compared to already available polyaniline‐silk composites. Further the studies have been extended to assemble a symmetrical two‐electrode supercapacitor device which also exhibits a high value of specific capacitance of 35 Fg−1 at 5 Ag−1 and 96.12% capacity retention over 5000 cycles. For the first time, this study reports using a Polyaniline‐Eri nanosilk composite to design an efficient supercapacitor electrode.