Water electrolysis using renewable electricity is a promising strategy for high-purity hydrogen production. To realize the practical application of water electrolysis, an electrocatalyst with high redox properties and low cost is essential for enhancing the sluggish oxygen evolution reaction (OER). Herein, we fabricated Fe-doped nickel oxalate (Fe-NiC2O4) directly grown on Ni foam as an efficient electrocatalyst for the alkaline OER using a facile one-step hydrothermal method. Fe-NiC2O4 served as a precursor for obtaining highly active Fe-NiOOH via in-situ electrochemical oxidation. Consequently, 0.75Fe-NiOOH was demonstrated to be the optimal electrocatalyst, exhibiting outstanding OER activity with a low overpotential of 220 mV at a current density of 100 mA cm−2 and a Tafel slope of 20.5 mV dec-1. Furthermore, Fe-NiOOH maintained its OER activity without performance decay during long-term electrochemical measurements, owing to the phase transformation from NiOOH to γ-NiOOH. These performances significantly surpass those of recently reported transition metal-based electrocatalysts.