Hydrogen produced from water splitting is a good alternative to conventional energy sources such as fossil fuels. A highly porous cobalt molybdenum sulfide (CoMoS₄) electrocatalyst was fabricated using a simple chemical synthesis route. The porous CoMoS₄ acts as an active electrocatalyst in alkaline medium for the oxygen evolution reaction with a low overpotential of 256 mV to reach a current density of 10 mA/cm². CoMoS₄ also acts as an active catalyst for the hydrogen evolution reaction at a current density of 10 mA/cm² at an overpotential of 143 mV. An alkaline electrolyzer cell was built where CoMoS4 was used as both the anode and cathode for the overall water splitting reaction with a current density of 10 mA/cm2 at a cell voltage of 1.65 V, which confirms the promise of this bifunctional electrocatalyst for overall water splitting.