As hydrogen energy technologies gain momentum, the role of renewable energy in facilitating sustainable hydrogen production is becoming increasingly critical. As a hydrogen production method, water electrolysis has attracted much attention from researchers due to its operational simplicity, the high purity of the hydrogen generated, and its potential for achieving zero carbon emissions throughout the process. Numerous studies has been manipulated on platinum (Pt)-based catalysts, which exhibit superior performance in hydrogen evolution reactions. Within this category, Pt nanoclusters stand out due to their unique attributes, such as quantum size effects and unique coordination environments. These features enable them to outperform both Pt metal atoms and nanoparticles in hydrogen evolution reactions regarding activity and stability. Here, we primarily delve into the reaction mechanisms underlying Pt nanocluster-based hydrogen catalysts, with particular emphasis on the interactions between the metal catalysts and their associated support materials. We provide an exhaustive summary of the strategies employed in the synthesis, the structural analyses conducted, and the performance metrics observed for Pt nanocluster catalysts when paired with various supporting materials. In closing, we explore the future potential and challenges facing Pt nanocluster-based catalysts in the context of industrial water electrolysis, along with emerging avenues for their design and optimization.