Manganese chloride tetrahydrate is widely used in various industrial and laboratory applications. It serves as a precursor in the synthesis of other manganese compounds, which are essential in the production of fertilizers, animal feed additives, dietary supplements, and pigments. In the field of chemistry, it acts as a catalyst in organic reactions, particularly in oxidation processes and the production of pharmaceuticals.

In the electronics industry, it is utilized in the manufacturing of batteries, including dry cell and lithium-ion types, and as a component in the production of pigments and dyes. In the glass and ceramics industry, it helps adjust colors and enhance optical properties. Additionally, it plays a role in wastewater treatment, where it helps in the removal of impurities and heavy metals. Its hygroscopic nature makes it useful in humidity control applications.

In research, manganese chloride tetrahydrate is employed as a source of manganese ions in biochemical studies, particularly in investigating enzyme functions and cellular processes. It is also used in the preparation of culture media for microbiological studies and in laboratory chemical education and research.