In the field of energy conversion and storage, the cost-effective and highly active oxygen evolution reaction (OER) catalysts are in much demand. Herein, morphology dependant OER activity of Co3S4 thin film electrodes fabricated using simple and cost effective successive ionic layer adsorption and reaction (SILAR) method is demonstrated for the first time. The morphology of Co3S4 has been influenced by varying number of deposition cycles. The effect of change in morphology on the electrocatalytic properties of Co3S4 thin film electrode is studied. The OER performance of Co3S4 thin film is related to the morphology. The OER activity with an overpotential of 275 mV @10 mA cm−2 and Tafel slope of 53 mV dec−1 in 1 M KOH electrolyte is due to increased electrochemical active surface area, super-hydrophilic nature, and low electron transfer resistance of Co3S4 thin film electrode.