Electrocatalytic water splitting/electrolysis are accomplished by employing a precious noble metal and metal oxide catalyst. Due to their limited availability and high cost, recent research has focused on the development of earth abundant, low cost, eco-friendly and non-precious catalysts. Towards this goal, this work aims to the study the effect of Ni doping in Mn₃O₄ for OER in alkaline medium. Mn₃O₄ and Ni doped Mn₃O₄ were synthesized through a simple CTAB assisted co-precipitation reaction followed by calcination. The physical and chemical properties associated with the catalytic activity of the samples were investigated. The results suggest that an optimum of 10 wt% Ni doped Mn₃O₄ exhibits better catalytic activity compared to pure Mn₃O₄. It shows a lower overpotential of η = 283 mV vs. RHE at 10 mA cm⁻², η = 235 mV vs. RHE at 5 mA cm⁻² and Tafel slope of 165 mV dec⁻¹ compared to pure Mn₃O₄ and 1 and 5 wt% Ni doped Mn₃O₄. The overpotential obtained in the present study is lower than that of the recent studies on Mn₃O₄, graphene–Mn₃O₄, Pt–Mn₃O₄ and Pd–Mn₃O₄.