In the title sulfonamide derivative, C11H10ClN3O2S, the dihedral angle between the pyridine rings is 46.85 (12)°. The N atom of the chloro-pyridine ring is anti to the N-H bond. In the crystal, mol-ecules are linked through N-H⋯N hydrogen bonds into zigzag chains parallel to [001] with a C(7) graph-set motif.