Osmium octafluoride is an inorganic chemical compound of osmium metal and fluorine with the chemical formula OsF8.

[3][4] Some sources consider it to be a still hypothetical compound.

[5] An early report of the synthesis of OsF8 was much later shown to be a mistaken identification of OsF6.

[6] Theoretical analysis indicates OsF8 would have an approximately square antiprismatic molecular geometry.

[7] Rapid cooling of fluorine and osmium reaction products:[8] This inorganic compound–related article is a stub.