A mild and efficient protocol for C4-H sulfonylation of 1-naphthylamine derivatives with sodium sulfinates has been described. This C4 sulfonylation proceeded smoothly at room temperature under Ru/Cu photoredox catalysis or Cu/Ag cocatalysis and could tolerate various functional groups. In addition, control experiments suggested that this C4-H sulfonylation reaction might proceed via a single-electron-transfer process.