In the title compound, C(18)H(15)N(5)O(2)S, a weak intra-molecular C-H⋯S hydrogen bond results in a small dihedral angle of 3.71 (9)° between the methyl-phenyl and triazole rings, which, in turn, form dihedral angles of 80.09 (8) and 77.32 (8)°, respectively, with the benzoxazolone mean plane. In the crystal, N-H⋯O hydrogen bonds link mol-ecules into chains along [001], and weak C-H⋯N hydrogen bonds and π-π inter-actions between the five- and six-membered rings [centroid-centroid distances = 3.5074 (11) and 3.616 (1) Å] consolidate the crystal packing.