The title mol-ecule, C(16)H(13)ClO(2), is trans with respect to the C=C double bond. The dihedral angles between the mean plane of the prop-2-en-1-one unit and those of the 3-chloro- and 4-meth-oxy-substituted benzene rings are 20.93 (9) and 20.42 (10)°, respectively, and the dihedral angle between the mean planes of the two benzene rings is 40.96 (5)°. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds, forming chains along the b axis.