Over the past few decades, numerous 3d transition metal (TM)-based layered oxide cathodes have been explored to act as OER catalysts. It has also been reported that the properties of a Co-based, efficient OER electrocatalyst, particularly Co3O4 , can be effectively tuned up by lithium insertion/(de)insertion as in LiCoO2. Apart from a single 3d TM containing OER electrocatalysts, a dual 3d TM Fe-substituted LiNiO2 has also been reported to be an efficient electrocatalyst. The higher activity of this doubly doped layered oxide is attributed to the higher oxidation states of TMs and their stabilization in layered structures. So far, several layered oxides have only been looked upon as a suitable host for stabilizing the highly oxidized TM species necessary for effective OER catalysis. Though layered oxides are better suited to stabilize oxidized TM species, it has also been predicted that the electronic state regulation is another avenue to enhance the activity of perovskite electrocatalysts. In this realm, doping is an effective strategy to tailor the oxidation states of TM ions in layered oxides, to effectively promote hole hopping between TM n to TM (n+1) ions. 12. However, the binding energy (BE) of surface oxygen is another vital aspect in OER catalysis, which has rarely been considered in previous reports. Thus, efforts must be substantiated to understand the role of BE of TMs with surface oxygen in the presence of doped cations/anions. Herein we report, for the very first time, a uniquely combined 3d/4d TMs-based cation disordered rocksalt (DRX) cathode material with Na-substitution in the lattice framework by the facile solid-state route. This uniquely combined 3d/4d TMs DRX cathode is believed to entirely change the stacking sequence to that of just 3d TMs cathode, while doping of monovalent cation substitution assists in promoting the oxidation state of TMs. The X-ray diffraction and other characterization techniques reveal that Na-substitution significantly assists in OER. The Na-substituted disordered cathode achieves a small Tafel slope of 67.5 mV dec -1 , η of 270 mV at a current density of 10 mA cm -2 , better than that of the IrO2 benchmark catalyst, and long-term stability over 133 hours. The machine learning aid to search for the minimum energy structure along with density functional theory (DFT) calculations reveals that the oxygen BE is ~6.51 eV in pristine. In comparison, it is much lower (~5.45 eV) in Nasubstituted cathode. The higher activity in Na-substituted DRX cathode is attributed to the facile desorption of O2 from the surface (Scheme 1). Scheme1. Schematic illustration of facile O2 desorption from the surface.