Iridium hexafluoride, also iridium(VI) fluoride, (IrF₆) is a compound of iridium and fluorine and one of the seventeen known binary hexafluorides. It is one of only a few compounds with iridium in the oxidation state +6.

Iridium hexafluoride is made by a direct reaction of iridium metal in an excess of elemental fluorine gas at 300 °C. However, it is thermally unstable and must be frozen out of the gaseous reaction mixture to avoid dissociation.

Iridium hexafluoride is a yellow crystalline solid that melts at 44 °C and boils at 53.6 °C. The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.411 Å, b = 8.547 Å, and c = 4.952 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 5.11 g·cm⁻³.

The IrF₆ molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (O_h). The Ir–F bond length is 1.833 Å.

Calculations suggest that fluorine might react with iridium hexafluoride at 39 GPa to form IrF₈.

It is able to oxidize elemental chlorine to the blue-colored salt Cl
₄IrF
₆ (containing Cl₄⁺, originally misidentified as Cl₂⁺), in a process somewhat analogous to the oxidation of elemental oxygen by PtF₆ (which yields the O₂⁺ containing O
₂PtF
₆).