The first spectrosopic evidence for the existence of the CF3OSO3 radical has been obtained from matrix isolation and FT-IR and UV spectroscopic studies. The vibrational frequencies measured are in reasonable agreement with predictions from density functional calculations. Upon visible and UV photolysis of the CF3OSO3 radical, SO3 is produced and provides experimental support for a new light-driven route for the oxidation of SO2 to SO3 assisted by CF3O radicals.