Used as a catalyst in the decomposition of hydrogen peroxide, manganese dioxide helps rapidly break down the solution into water and oxygen. It is commonly employed in laboratories and industrial processes for this purpose due to its efficiency and reusability.

In dry-cell batteries, such as zinc-carbon and alkaline batteries, it acts as the cathode material and depolarizer, preventing the buildup of hydrogen gas and maintaining consistent electrical output.

Manganese dioxide is also utilized in the production of chlorine gas from hydrochloric acid through oxidation reactions and in the production of ferrites for electronic components, including inductors and transformers, where it contributes to magnetic properties.

In glass and ceramic manufacturing, it serves as a colorant and decolorizer. It can impart a purple, black, or brown tint or neutralize green tints caused by iron impurities in glass.

Additionally, it is used in wastewater treatment to remove dissolved iron and manganese compounds by promoting precipitation and facilitating their separation from water.

In organic synthesis, manganese dioxide is employed for the selective oxidation of allylic and benzylic alcohols to their corresponding carbonyl compounds (aldehydes or ketones), particularly in reactions requiring high specificity without damaging other functional groups in the molecule.