The title compound, C16H10N2S, is almost planar (r.m.s. deviation for all non-H atoms = 0.080 Å). The dihedral angle between the three fused-ring system and the phenyl ring is 9.26 (3)°. The S atom and the opposite C atom of the thiophene ring are mutually disordered with an occupancy ratio of 0.7706 (19):0.2294 (19)