The title mol-ecule, C23H20O3, is disordered with a 180° rotation about an axis normal to the length of the mol-ecule, with the major and minor components in a 0.545 (5):0.455 (5) ratio. In the major component, the central benzene ring forms dihedral angles of 72.34 (3) and 69.46 (3)° with the dimethyl-substituted and meth-oxy-substituted benzene rings, respectively. Moreover, the central benzene ring forms dihedral angles of 50.86 (5) and 58.43 (4)° with the mean planes of the ketone groups. In the minor component, the corresponding dihedral angles between the benzene rings are 71.36 (4) and 67.94 (4)° and the dihedral angles between the benzene ring and the ketone groups are 56.44 (9) and 55.51 (8)°. In the crystal, C-H⋯O inter-actions generate a C(9) chain along the a-axis direction.