In the title compound, C16H10Cl2N2O2S, the dihedral angles formed by the chloro-substituted benzene rings with the central oxa-diazole ring are 6.54 (9) and 6.94 (8)°. In the crystal, C-H⋯N hydrogen bonding links the mol-ecules into undulating ribbons running parallel to the b axis. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are the H⋯C (18%), H⋯H (17%), H⋯Cl (16.6%), H⋯O (10.4%), H⋯N (8.9%) and H⋯S (5.9%) inter-actions.