AbstractA novel tetranuclear copper‐based water oxidation catalyst was designed and synthesized by using a new multinucleating ligand containing two proton dissociation sites, 1,3‐bis(6‐hydroxy‐2‐pyridyl)‐1H‐pyrazole. The copper complex showed electrocatalytic activity for water oxidation reactions under aqueous basic conditions (pH 12.5) with an overpotential of approximately 500 mV. UV/Vis absorption and energy‐dispersive X‐ray (EDX) spectroscopic techniques coupled with electrochemical analyses of the catalyst system strongly suggest that the tetranuclear copper complex works as a homogeneous system under the conditions used. The results described here demonstrate the utility of a discrete tetranuclear copper complex in water oxidation reactions.