In the title mol-ecule, C(24)H(19)NO(6)S, the heterocyclic thia-zine ring adopts a half-chair conformation with the S and N atoms displaced by 0.180 (5) and 0.497 (5) Å, respectively, on opposite sides of the mean plane formed by the remaining ring atoms. The benzene rings of the benzothia-zine unit and the meth-oxy-phenyl group are almost coplanar, with the dihedral angle between the mean planes of these rings being 5.9 (2)°, while the benzene ring of the 2-oxo-2-phenyl-ethyl group is inclined at 79.68 (11) and 81.01 (10)°, respectively, to these rings. The mol-ecular structure is consolidated by intra-molecular O-H⋯O and C-H⋯N inter-actions, and the crystal packing is stabilized by weak C-H⋯O hydrogen bonds.