Achieving a future sustainable carbon-neutral society requires the development of efficient systems for the chemical conversion of solar light energy to CO₂-free fuels such as H₂ as alternatives to fossil fuel. In this case, water splitting driven by solar energy is one of the most promising approaches for sustainable H₂ production. However, the critical bottleneck in establishing efficient water splitting systems is the sluggish oxygen evolution reaction (OER) with high overpotentials (η_O2). Thus, the development of highly efficient OER electrocatalysts to minimize η_O2 and thus attain efficient water splitting is a challenging key task. Recently, there has been prominent progress in the development of efficient Ni-based electrocatalysts with extremely low η_O2. Herein, the aspects and mechanisms of state-of-the-art Ni-based OER electrocatalysts reported in the last three years from 2020 to 2023 are reviewed. Furthermore, we discuss the perspectives to develop efficient Ni-based OER electrocatalysts based on the comprehensive understanding of the catalysts introduced in this review.