The present article report on synthesis and electrochemical supercapacitor application of bismuth oxide (Bi2O3) deposited on stainless still (SS) substrate using a low cost and simplest electrodeposition methods. The structural analyses of the produced samples reveal polycrystalline with a tetragonal crystal structure. It has been obtained to synthesized linked adherence and compact surface morphology and TEM reveals nanoplates-like surface appearance. Electrochemical supercapacitive concert of Bi2O3 thin film electrode has been performed through cyclic voltammetry (CV), charge-discharge (CD), and impedance spectroscopy (EIS) in aqueous 1M KOH electrolyte. The Bi2O3 thin film electrode obtained the highest specific capacitance (SC) of 1227.5 F/g at 2 mV/Sec scan rate in 1M KOH. The obtained maximum value of specific energy (SE) and specific power (SP) was 191.14 Wh/Kg and 4.8 kW/kg at 18 mA/cm2 in 1M KOH electrolyte respectively. 93.29 % capacitance retention after 3500 CV cycles.