In the crystal structure of the title compound, C(7)H(4)Cl(2)O, the mol-ecules form a network of weak C-H⋯O inter-actions involving the aldehyde O atom and the ortho-H atom on the benzene ring together with C-H⋯O inter-actions between the formyl groups. Together, these connect the mol-ecules into (10) layers, which are stabilized additionally by π-π stacking inter-actions of the benzene rings [centroid-centroid distance = 3.772 (1) Å]. The aldehyde group is twisted relative to the benzene ring by 7.94 (13)°.