Potassium hexafluoronickelate(IV) is an inorganic compound with the chemical formula K2NiF6.

It can be produced through the reaction of potassium fluoride, nickel dichloride, and fluorine.

It reacts violently with water, releasing oxygen.

It dissolves in anhydrous hydrogen fluoride to produce a light-red solution.

It can turn chlorine pentafluoride and bromine pentafluoride into ClF+6 and BrF+6, respectively:[4] Potassium hexafluoronickelate decomposes at high temperatures to release fluorine gas; like terbium(IV) fluoride, the emitted fluorine is primarily monatomic rather than the typical diatomic.