Sulfonium salts are playing an increasingly significant role in contemporary organic synthesis.I n particular,t he generation of radicalsf rom sulfonium salts is af undamental process in Naturea nd has been the subject of investigation for over 50 years. However, general synthetic methods that use sulfonium salts as radical precursors are rare.T he advent of photoredox catalysis hast riggered an upsurge of interesti nt he radical chemistry of sulfonium salts and this review surveys recent applications of aryl-and alkylsulfonium saltsi nl ight-mediated, radical C À C bond formation. 1I ntroduction 2E arly Reports on the Photochemistry of Sulfonium Salts 3S ulfonium Salts in C À CB ond Formation 3.1 TheV alue of Arylsulfonium Salts in Light-Mediated C À CB ondF ormation 3.2 TheP reparation of BenzylsulfoniumSalts and their Reactivity in Light-Mediated C À CB ond Formation 3.3 TheD irect Preparation of Arylsulfonium Salts for Light-Mediated C À CB ond Formation 4C onclusion