In the title compound, C19H22FN3OS, the dihedral angle between the inclined oxa-diazole and benzene rings is 52.7 (3)°. In the crystal, helical supra-molecular chains along [100] are sustained by N-H⋯S hydrogen bonds supported by methyl-ene-benzene C-H⋯π inter-actions. The crystal studied was an inversion twin with the fractional contribution of the minor component being 0.33 (14).