m-Tolylhydrazine hydrochloride is primarily used in organic synthesis as a key reagent for the preparation of various heterocyclic compounds. It serves as a building block in the synthesis of pharmaceuticals, particularly in the development of drugs targeting the central nervous system. The compound is also employed in the production of dyes and pigments, where it acts as an intermediate in the creation of complex colorants. Additionally, it finds application in agrochemical research for the development of pesticides and herbicides. Its role in coupling reactions makes it valuable in the synthesis of azo compounds, which are widely used in the textile industry for dyeing processes.