Barium permanganate is a chemical compound, with the formula Ba(MnO4)2.

[2] It forms violet to brown crystals that are sparingly soluble in water.

Highly pure samples can be obtained from the similar reaction between potassium permanganate and aluminium sulfate to form aluminium permanganate, which is then reacted with a stoichiometric amount of barium hydroxide.

[5] The decomposition has been shown to proceed at slow rates above 160 °C, and that irradiation with UV or X-rays lowers this temperature.

[6] Crystal defects and impurities play a role in the mechanism.