Transition metal chalcogenides become emerging materials as electrodes for electrochemical energy storage devices. In this study, we are reporting the preparation of α-MnSe nanoparticles using a one-pot hydrothermal method and examined its use as an electrode material for supercapacitors. Physico-chemical characterizations such as X-ray diffraction, laser Raman, and field emission scanning electron microscopic analyses revealed the formation of α-MnSe nanoparticles. The electrochemical analysis such as cyclic voltammetry and electrochemical impedance spectroscopy suggested the mechanism of charge-storage is due to the pseudocapacitive nature of α-MnSe electrode. The α-MnSe electrode delivered a specific capacitance of 96.76 F g−1 from galvanostatic charge-discharge obtained at a constant current density of 0.1 mA cm−2 with a corresponding energy density of 8.60 Wh kg−1 and better cyclic stability over 2000 cycles. Further, the electrochemical performance of the α-MnSe symmetric supercapacitor device shows that the specific capacitance is about 23.44 F g−1 at a current density of 0.1 mA cm−2, with a potential window of 0.8 V. The superior electrochemical performance of α-MnSe highlights the potential use as electrode material in energy storage sector.