This work presented a simple electrodeposition of hierarchical cobalt oxide nanoparticles on stainless steel mesh (Co3O4@SS) for electrocatalytic water oxidation. The synthesized Co3O4@SS are systematically characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and field emission scanning electron microscopy with energy dispersive spectrum (FE-SEM with EDS). Further, the electrocatalytic water oxidation performance of hierarchical Co3O4@SS is examined and compared to bare stainless steel mesh (bare SS) through linear sweep voltammetry (LSV), linear Tafel polarization and electrochemical impedance spectroscopy (EIS) methods in 0.1 M aqueous KOH. The presence of clear and sharp FT-IR bands of Co3O4@SS at 658 and 554 cm� 1 indicated the formation of oxides. The XRD pattern of Co3O4@SS show additional 2θ peaks than that of bare SS, which are assigned for crystalline Co3O4. The FE-SEM with EDS of Co3O4@SS reflects the porous hierarchical morphology along with the presence of Co, O, Fe and Cr elements. Moreover, the electrochemical results such as LSV, Tafel and EIS revealed good electrocatalytic activity of Co3O4@SS towards water oxidation. All the results suggested that the electrodeposited Co3O4@SS can act as a better candidate for electrocatalytic water oxidation. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.