Used as a catalyst in the decomposition of hydrogen peroxide, manganese dioxide speeds up the breakdown into water and oxygen without being consumed in the reaction. It is commonly employed in laboratories and industrial processes for this purpose.

In dry-cell batteries, such as zinc-carbon and alkaline batteries, it acts as a depolarizer and cathode material, preventing the buildup of hydrogen gas and facilitating the conversion of chemical energy to electrical energy.

Manganese dioxide is used in the production of ferrites for electronic components like inductors and transformers due to its magnetic properties.

It serves as an oxidizing agent in organic synthesis, particularly in the oxidation of allylic alcohols to carbonyl compounds, and in various processes including the synthesis of vitamins.

In glassmaking, it helps remove the green tint caused by iron impurities by oxidizing iron to a higher state, resulting in a clearer product, or to impart purple or brown colors as desired.

It is also utilized in the manufacture of bricks and ceramics to reduce discoloration and improve color consistency.

In wastewater treatment, manganese dioxide oxidizes soluble iron and manganese compounds to insoluble forms that can be easily precipitated and removed.

Additionally, it is used in cosmetics, such as lipsticks and eyeshadows, as a natural colorant providing brown shades, safe when used in appropriate concentrations.