The oxygen evolution reaction (OER) is the primary challenge in renewable energy storage technologies, specifically electrochemical water splitting for hydrogen generation. The development of affordable, robust, and efficient OER electrocatalysts plays a prominent role in water splitting by lowering the reaction kinetics barrier and boosting the performance of the process. This review discusses the recent progress in probing the electronic structure of catalytically active materials and its relevance to OER activity. We have aimed to emphasize state-of-the-art engineering strategies for modulating the electronic structure to exhibit ideal OER performance, including doping, alloying, generation of oxygen vacancies, heterostructure realization, and strain engineering. Finally, we summarize the existing challenges and opportunities in electronic structure modulation for future electrocatalyst development.