Triiodine fluorosulfate is the inorganic compound with the chemical formula . It is the fluorosulfate () salt of the polyhalogen ion.
Triiodine fluorosulfonate is obtained from iodine and iodine(I) fluorosulfonate at 85 ðC.
Also, a reaction of iodine with peroxydisulfuryl difluoride:
The compound hydrolyzes well in water and dissolves in sulfuric acid.
It reacts with tetrafluoroethylene () to form and .