In the title compound, C(30)H(34)N(4)S, each of the benzothia-diazole and fluorene fused ring systems is almost planar (r.m.s. deviations = 0.010 and 0.013 Å, respectively) and they are inclined to each other with a dihedral angle of 61.69 (3)°; the S atom is directed away from the rest of the mol-ecule. Each of the benzothiadiazole ring N atoms forms a significant intra-molecular contact, i.e. N-H⋯N or C-H⋯N. In the crystal, linear supra-molecular chains along the c axis are generated by C-H⋯N inter-actions involving the tertiary amine N atom.