In the title compound, C(22)H(15)NO(3)S, the plane of the carbazole ring system forms a dihedral angle of 65.06 (4)° with the naphthalene ring system. In the crystal structure, a weak intra-molecular C-H⋯O inter-action is observed between the naphthalene ring system and the sulfonate group. Two weak inter-molecular C-H⋯O inter-actions are also observed.