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 laboratory settings for oxygen generation. Additionally, it serves as a catalyst in the Deacon process for producing chlorine from hydrogen chloride via oxidation.

In dry-cell batteries, such as alkaline and zinc-carbon batteries, it acts as a depolarizer and cathode material, preventing voltage drop by reducing polarization and inhibiting hydrogen gas evolution.

Also utilized in the production of ferrites for electronic components, it contributes to the magnetic properties of these materials. In glass and ceramic manufacturing, it serves as a colorant and decolorizer, helping to remove green tints caused by iron impurities or adding black, purple, or pink hues.

Additionally, it plays a role in the oxidation of organic compounds in industrial chemical synthesis and environmental remediation, such as treating hydrogen sulfide in wastewater. It is also used in water treatment to remove excess iron and manganese as an adsorbent in filtration systems.