Electrocatalytic water splitting is one of the most effective ways to produce hydrogen as a clean energy carrier for the future of global energy provision that enables the production of energy to become independent of fossil fuels. In this work, we present a two-step hydrothermal method as a synthesis approach for the preparation of MnCo2O4 nanoparticles loaded on porous γ-Al2O3 (Al2O3/Mn–Co). This composite was characterized by different techniques, and then it was used as an electrode material to create an electrocatalyst for water splitting with great performance. This composite exhibited enhanced electrocatalytic activity requiring an overpotential of ∼113 and ∼270 mV at the current density of 10 mA cm–2 for the reactions of HER and OER, respectively, and a comparatively low cell voltage (∼1.57 V) for overall water splitting. The Tafel slopes for HER and OER were 74 and 63 mV dec–1 and also show a long-range stability of 14 h. The present results would exhibit a new chance to design and develop a multicomponent electrocatalyst for the overall water electrolysis.