Iridium(IV) fluoride is a chemical compound of iridium and fluorine, with the chemical formula IrF<sub>4</sub> and is a dark brown solid. Early reports of IrF<sub>4</sub> prior to 1965 are questionable and appear to describe the compound IrF<sub>5</sub>. The solid can be prepared by reduction of IrF<sub>5</sub> with iridium black or reduction with H<sub>2</sub> in aqueous HF. The crystal structure of the solid is notable as it was the first example of a three-dimensional lattice structure found for a metal tetrafluoride and subsequently RhF<sub>4</sub>, PdF<sub>4</sub> and PtF<sub>4</sub> have been found to have the same structure. The structure has 6 coordinate, octahedral, iridium where two edges of the octahedra are shared and the two unshared fluorine atoms are cis to one another.