In the title compound, C20H16O3S, the dihedral angle between the mean planes of the naphtho-furan and 3-methyl-phenyl fragments is 88.56 (2)°. In the crystal, mol-ecules are linked via pairs of C-H⋯O hydrogen bonds, forming inversion dimers. These dimers are linked by π-π inter-actions between the furan rings of neighbouring mol-ecules [centroid-centroid distance = 3.701 (2) Å] into supra-molecular chains running along the a-axis direction.