In recent years, the global development of sustainable energy technologies has garnered increasing attention. Among these, water splitting has emerged as a promising method for renewable energy conversion, offering significant potential for hydrogen production. Two-dimensional transition metal dichalcogenides (2D-TMDs) have been recognized as ideal catalytic materials attributable to their unique layered structure, abundant active sites, and tunable electronic properties. Compared to conventional noble metal catalysts, TMDs offer advantages such as excellent stability, low cost, and high activity. Furthermore, optimizing material structures, enhancing electrical conductivity, and elucidating catalytic mechanisms, through heterostructure design and advanced analytical techniques, could further improve the catalytic efficiency of 2D-TMDs. These developments are expected to drive the improvement of high-performance water-splitting catalysts and contribute to the progress of sustainable energy technologies. This chapter summarizes recent advances in the application of 2D-TMDs for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with a particular focus on their synthesis methods and catalytic performance, providing insights on their practical implementation in industrial water-splitting systems.