Diaryliodonium salts have been used as aryl radical sources under visible light-mediated photoredox catalysis. Benzene and a range of heteroarenes are arylated with Ar2I+ in the presence of [Ir(ppy)(2)(bpy)]PF6 upon irradiation with visible light. When pyrroles are used, the arylation proceeds in the absence of a photoredox catalyst. Both processes are initiated by photoinduced single-electron-transfer to Ar2I+, generating aryl radicals.