MoS2 structures with large surface areas and edges for use as electrocatalysts in the hydrogen evolution reaction (HER) are typically synthesized via solvothermal and hydrothermal methods. However, to utilize the fabricated particles as electrodes, they should be applied on substrates in the form of inks; this requires additional processing. Furthermore, if the electrode has a three-dimensional structure with more than two sides, applying the ink to the entire surface is difficult. Therefore, there is a requirement for a thin-film deposition process based on a fast reaction that does not require toxic substances and can be used for one-pot electrode fabrication. In this study, we present a rapid, one-step hydrothermal electrodeposition technique for the formation of MoS2 thin films on glassy carbon substrates. The MoS2 electrocatalysts fabricated using this method have surfaces that are rich in metallic phases, and they exhibit good activity as hydrogen evolution catalysts. This hydrothermal electrodeposition technique is expected to be broadly applicable to various electrodes and other technologies.